Is touch sensitivity higher for females? I read a long time ago that in a study of two-week old infants response to touch, the female babies were far and away more sensitive. In most gender comparisons, there are the familiar "two humps" in the distribution of responses, but in this case, the male and female response ranges did not even overlap: the most sensitive male infant was less sensitive than the least sensitive female.

Has this sort of difference been shown in more recent research and with other age groups? It seems to me that it would have to be innate, because two weeks is not a long time to be affected by cultural differences. I would think that this difference would persist with age, and would explain a lot of the difference in how men and women function during sex, or any sort of intimate touch.

Short answer
Females are more sensitive to some, but not all somatosensory stimuli. Males are either less sensitive, or as sensitive as females.

Background
A normative study by Blankenburg et al. (2010) determined reference values for a battery of somatosensory tests including cold detection threshold (CDT); warm detection threshold (WDT); thermal sensory limen (TSL); cold pain threshold (CPT); hot pain threshold (HPT); pressure pain threshold (blunt pressure, PPT); mechanical pain threshold (pinprick, MPT); mechanical pain sensitivity (pinprick, MPS); wind-up ratio (WUR); mechanical detection threshold (MDT); vibration detection threshold (VDT) in male and female subjects in the age range of 6 - 16 years.

Girls were significantly more sensitive to CDT, WDT, TSL, CPT, HPT and PPT.

No significant difference was found for MPT, MPS, WUR, MDT or VDT.

However, the authors note that some of their findings did not match that of other studies. For example, better thermal detection in female than in males as found in their study matches the data in adults of previous studies, but did not match other studies that also used kids. The lack of sex-dependency of mechanical pain sensitivity contrasted other studies in children and adults.

I would suggest reading Blankenburg et al. (2010) for more details.

Another study showed female infants to have lower electro-tactile thresholds (are more 'sensitive') than age-matched males (Lipsitt, 1959).

References
- Blankenburg et al. Pain (2010); 149: 76–88
- Lipsitt, Child Development (1959); 30(4): 547-54


Are people able to accurately judge body shape and size from images of the face? I have noticed that when I look at a cropped picture of someone's face, I fill in the remaining image of his/her body in a manner that is consistent with the face (wider face, larger body, skinnier face, frail body, large jaw, more muscular body, etc).
Does the human brain immediately and accurately fill in such information and guess what a persons's body looks like from just images of the face?

Yes, barring weird instances of swelling that is localised to the face, for example. Evolutionary psychologists argue that facial cues, including adiposity and skin pigmentation, to name but two, serves as a cue for general health. If this argument holds true, it means that humans developed a fine-tuned ability to make quick judgments about someone's fitness to mate based on various factors related to health, of which facial features happens to be a big one. This might also explain why we find highly symmetrical faces more attractive, as facial symmetry is positively correlated with genetic health markers.

Another example is the seemingly robust correlation between testosterone levels and the square jaw that you mentioned. In turn, testosterone and muscle mass are linked. Ao seeing someone with a square jaw, you automatically infer their testosterone levels as well.

Apart from that, there is an obvious correlation between facial adiposity and BMI, which heavily influences judgments about general health and mating preference.

Short answer: You have this ability because it's highly advantageous when it comes to making judgments about choosing good mates.


The relationship between creativity and focus From what I have read here and there, I've managed to stitch together some superficial understanding of focus and creativity. My understanding is that focus and creativity seem like opposites.

I've seen references (which all seem to originate from a coursera course on learning) to two distinct "modes of thought". One called 'Focused' and one called 'Diffuse'. In focused mode, we focus on doing something we already know how to do. In Diffuse mode, we don't focus on a specific task we are instead searching for a way to do something, until we come up with an idea - it is at that point we focus on completing a task.

Whether this view of thought is scientifically grounded or not, there does seem to be some truth to it: the default mode network, whose activity is reduced during certain types of meditation (at least, according to wikipedia), from what i can understand is linked to creativity . The explanation of this default mode seems similar to the "diffuse" mode of thought.

It seems (at least, to me), that focus and creativity are opposites - which makes sense in some ways. But is it really so?

Are creativity and focus competitive as far as the brain structures that support these are concerned? That is, if I improve my ability to focus, will it interfere with my ability to be creative?
This seems somewhat ridiculous to me, but I suspect it's only because I want to believe it isn't so. For the moment, my understanding is that creativity and focus are separate,  and require "switching" between them, which leads to the next question:
Are creativity and focus competitive as far as brain activity goes? that is, if I try to focus on something right now, will it interfere with my ability to be creative? If I focus on solving a problem I know how to solve, I probably won't be looking for a creative solution (also, there is the Einstellung effect). But does the same mechanism responsible for maintaining or focus interfere with our ability to be creative at the moment?

I can't really answer your questions as they relate to your ability to be creative. Also I'm unsure as to how 'focus' is defined, however, I know of research linking both attention and working memory to creativity which you may be able to draw conclusions from.

There is some mixed research to back the idea creativity and attention are linked; it has been hypothesised that individuals who suffer from ADHD (and thus a widened attentional focus) may have higher creative abilities than non ADHD individuals. One study on teens found that although those with ADHD out performed those without on tasks that involve overcoming the influence of examples, they showed a reduced capacity to generate a functional invention during an imagery task (Abraham et al 2006). White and Shah (2006) found similar results in adults and suggest than the disparity in creative ability may be linked to inhibition.

There has also been some research suggesting that creativity and capacity of working memory have opposing characteristics possibly in terms of diffuse attention. Working memory (WM) is an essential component for human
higher order cognitive activities (large capacity for WM could come under 'focus'). Attention and WM share neural substrates and they are cognitively deeply associated (Awh and Jonides, 2001). Takeuchi et al used fMRI to investigate the link between WM and creativity and found that individual creativity, as measured by the divergent thinking test, is related to the inefficient reallocation of attention, congruent with the idea that diffuse attention is associated with individual creativity.

References:

Abraham, A., Windmann, S., Siefen, R., Daum, I., & Güntürkün, O. (2006). Creative thinking in adolescents with attention deficit hyperactivity disorder (ADHD). Child Neuropsychology, 12(2), 111-123.

White, H. A., & Shah, P. (2006). Uninhibited imaginations: creativity in adults with attention-deficit/hyperactivity disorder. Personality and Individual Differences, 40(6), 1121-1131.

Takeuchi, H., Taki, Y., Hashizume, H., Sassa, Y., Nagase, T., Nouchi, R., & Kawashima, R. (2011). Failing to deactivate: the association between brain activity during a working memory task and creativity. Neuroimage, 55(2), 681-687.

Awh, E., & Jonides, J. (2001). Overlapping mechanisms of attention and spatial working memory. Trends in cognitive sciences, 5(3), 119-126.


What is the current state of knowledge on the roles and mechanisms of top-down information flow in the brain? I have heard that "90% of information flow in the brain (or maybe it was just the visual cortex) is top-down".  I'm not sure if this claim is substantiated, but I do get the impression that there is strong evidence that at least most of the information flow is top-down.  I'd like to know as specifically as possible what current theories in neuroscience say is going on here.  I'd appreciate details and reputable academic works.

No the brain doesn't in practice work in a single flow. It takes a combination of top-down and bottom-up at various frequencies to perform any task. Outside a laboratory the amount of time you spend going top-down or bottom-up will depend on what kind of life you lead.

  Hippocampal movement-related low-frequency oscillations are one of the most well-characterized and replicated findings across species. Previous literature has demonstrated that movement-related oscillations are distinct phenomenon from memory-related low-frequency oscillations. We suggest that movement-related oscillations arise, in part, due to entrainment from sensorimotor information inherited from upstream cortical areas and thus may represent largely bottom-up input. We also discuss memory-related low-frequency oscillations and their emergence when rodents retrieve information about which part of a maze to explore. These memory-related oscillations often appear coordinated between hippocampus and cortex and may reflect top-down, or rule based processing. The presence of both bottom-up and top-down low-frequency oscillations may be yet another example of spectral fingerprinting, in which different cognitive operations manifest in the same brain networks via different frequencies of synchronization. While many aspects of this idea remains to be tested, particularly in the context of navigation, we believe that these ideas represent one step in bringing some synchrony to an often desynchronized field on the study of neural oscillations.

-Multifaceted roles for low-frequency oscillations in bottom-up and top-down processing during navigation and memory


Effect of having false confidence because of confusion of familiarity and knowledge What is the name of the effect which causes one to skip information that feel familiar during learning due to the confusion of familiarity and knowledge?

Change blindness: failure to notice large changes to the visual scene [1].
If you are interested in familiarity change blindness I suggest this article [2].
Reference:
[1] Simons, D. J., & Levin, D. T. (1997). Change blindness. Trends in cognitive sciences, 1(7), 261-267.
[2] Tovey, M., & Herdman, C. M. (2014). Seeing changes: How familiarity alters our perception of change. Visual Cognition, 22(2), 214-238.


Is there a term that describes the personality trait of always desiring more? I see this kind of trait in some of the people who fear the commitment (in a marriage) since they don't want to have to renounce their vows when their feelings toward their spouses change.

I see this kind of trait also in those who go to discos to find a better partner, who looks for the perfection, who thinks they deserve more, they seem unable to be satisfied with what they have. It happens often with narcissism. I think it's a way to manage anxiety: "I'm not enough, I need external validation, I must be more and more to be sure I will always be loved, because I'm not good.. and the other will realize.. so he must love me really a lot".

Some people prefer not to build a good relationship because they are scared to lose the chance for their better relationship. Some expect to get very strong feelings and emotions from a relationship, and that they will find someone who is able to really "get" them.

I would call it the illusion of being able to fully satisfy our expectations, without the ability to renounce the things they have, or to be easily satisfied by them.

What could this phenomenon be named and related to?

I'm not entirely sure what you mean by "renounce," but you may find some answers to your question in the fields of social psychology and behavioral economics. The first part of your question describes someone who is unwilling to commit or make a decision for fear of losing out on future opportunities. There has been research to indicate that having more options when making a decision is actually stressful and can provoke anxiety (Ackerman, Gross, & Celly, 2014).

One recent study found that individuals who were presented with all options at once were more satisfied than those who were shown options one at at time (Mogilner, Shiv, & Iyengar, 2013). The individuals who were given options one at a time tended to imagine a better, ideal option was yet to come; the authors noted that these participants were less happy with their choices in part because of that hope. The introduction to this paper references several other papers which found that individuals who were focused on possible options were less satisfied with the choices they may and were less likely to stick with those choices because of the hope for "something better." The paper specifically cites several articles which indicate that a person's commitment to their romantic partner is not necessarily influenced by the partner's characteristics, but by the person's focus on other options (Gange´ and Lydon 2001; Johnson and Rusbult 1989; Lydon et al. 1999; Rusbult, Martz, and Agnew 1998). Similarly, Miller (1997) found that awareness of and attention to alternative partners was the highest predictor of failure in romantic relationships.

How people approach decisions also impacts how they address the options presented. In choice deferral, a person puts off a decision that requires difficult compromises (such as committing to one partner and thus losing the freedom to continue dating) in order to avoid the negative emotions linked to that decision (Luce, 1998). Some people may be more prone to this behavior than others. Schwartz and colleagues (2002) have proposed that people fall into two groups: those who seek to maximize their decision by finding the very best option out of choices presented (maximizers), and those who have an idea in mind of what would be an "acceptable" option and settle for the first choice that surpasses their expectations (satisficers). Maximizers are always on the look out for "the best," are less satisfied with their choices, more likely to "socially compare" their options to others, and more likely to experience regret (Ma & Roese, 2014). Another recent publication proposed that when individuals experience "choice closure," and stop re-evaluating the non-selected alternative options, satisfaction with choice can increase (Gu, Botti, & Farro, 2013).

Again, I am not certain I understood all of your question, but I hope that this provides you with a starting point to find the answer.

Ackerman, D., Gross, B. L., & Celly, K. S. (2014). Having many choice options seems like a great idea, but...: Student perceptions about the level of choice for a project topic in a marketing course. Journal of Marketing Education. April, e-pub ahead of print. Doi: 10.1177/0273475314522038

Gagne, F. M., & Lydon, J. E. (2001). Mindset and relationship illusions: The moderating effects of domain specificity and relationship commitment. Personality and Social Psychology Bulletin, 27(9), 1144-1155.

Gu, Y., Botti, S., & Faro, D. (2013). Turning the page: The impact of choice closure on satisfaction. Journal of Consumer Research, 40(2), 268-283. DOI: 10.1086/670252

Johnson, D. J., & Rusbult, C. E. (1989). Resisting temptation: Devaluation of alternative partners as a means of maintaining commitment in close relationships. Journal of Personality and Social Psychology, 57(6), 967-980.

Luce, M. F. (1998). Choosing to avoid: Coping with negatively emotion-laden consumer decisions. Journal of Consumer Research, 24, 409-433.

Ma, J., & Roese, N. T. (2014). The maximizing mind-set. Journal of Consumer Research, 41(1), 71-92. DOI: 10.1086/674977

Miller, R. S. (1997). Inattentive and contented: Relationship commitment and attention to alternatives. Journal of Personality and Social Psychology, 37(4), 758-766.

Mogilner, C., Shiv, B., & Iyengar, S. S. (2013). Eternal quest for the best: Sequential (vs. simultaneous) option presentation undermines choice commitment. Journal Of Consumer Research, 39(6), 1300-1312. doi:10.1086/668534

Rusbult, C. E., Martz, J. M., & Agnew, C. R. (1998). The Investment Model Scale: Measuring commitment level, satisfaction level, quality of alternatives, and investment size. Personal Relationships, 5(4), 357-391.

Schwartz, B., Ward, A., Monterosso, J., Lyubomirsky, S., White, K., & Lehman, D. R. (2002). Maximizing versus satisficing: Happiness is a matter of choice. Journal Of Personality And Social Psychology, 83(5), 1178-1197. doi:10.1037/0022-3514.83.5.1178


How should medication for the treatment of ADHD symptoms be calibrated? My understanding is that the treatment of ADHD symptoms with stimulant medication is a balancing act between alleviating ADHD symptoms, and not producing unwanted side effects like insomnia or anxiety.

My understanding also is that the drugs effect different people differently, and so finding the right dose of the right specific drug is an exercise of 'finding what works'.

The question is - how should a medical practitioner determine when and by how much to change a patient's medication schedule?

My understanding also is that the drugs effect different people differently, and so finding the right dose of the right specific drug is an exercise of 'finding what works'.
The question is - how should a medical practitioner determine when and by how much to change a patient's medication schedule?

I think you've answered your own question: titration of dose i.e. slow, incremental changes in dose until desired therapeutic response is achieved.
The best way to understand it is terms of pharmacokinetics: if a drug has a linear dose-response curve, then we can anticipate a slightly higher dose will result in a slightly greater therapeutic effect, and a slightly greater increase in side-effects. The point of titrating the dose is to either stop when one reaches a ceiling effect i.e. increasing the dose won't have any improvement in symptoms, because it will only increase the side-effects, which haven't reached a ceiling yet,.
This is essentially true for all psychiatric drugs, and the same rationale applies to all pharmacotherapies.
With regards to ADHD, my understanding is that severity of symptoms does not predict the dose of psychostimulants required. So the psychiatrist will typically hand a patient a bottle of amphetamine, some dosing instructions, and tell them to sort it out themselves over the course of a few weeks. The whole point with the use of psychostimulants for ADHD is that its mediated by dopaminergic hypofrontality. But if one goes overshoots the  therapeutic window, then it will result in worse cognitive functioning, etc.


Is there evidence to support the Dunning-Kruger effect? The well known Dunning-Kruger effect is oft cited as a general explanation for why people with limited expertise overestimate their abilities. Other than the initial research that described this cognitive bias, there seems to be little actual data to support it outside of a sit-down questionnaire or IQ test in a university setting. Driving is a well-known example (i.e. '80% of drivers consider themselves above average') although I note from a previous post, the evidence for the Dunning-Kruger effect in driving is mixed.

Is there any data to support the Dunning-Kruger in outside of a sit-down test performed by university students?

Yes, there are research showing a relationship between skills and not only "sit down tests". A systematic review by Madmood (2016) found "self-reported and demonstrated information literacy skills" supported the Dunning-Kruger phenomena. Demonstrated information literacy was from derived sources such as "observations, field notes, participant reflexive journals, expert grading of searching tasks, analysis of students’ theses, quizzes, and information related assignments".

References:

Mahmood, K. (2016). Do People Overestimate Their Information Literacy Skills? A Systematic Review of Empirical Evidence on the Dunning-Kruger Effect. Communications in Information Literacy, 10 (2), 199-213. https://doi.org/10.15760/comminfolit.2016.10.2.24


What is an example of a learning machine that achieves zero variance? I'm attempting to find an example of a learning machine/neural network that achieves zero variance, but I am having a hard time finding an example anywhere.

Variance is defined as the generalization error for a neural network or in other words the difference between the learning function derived from a specific sample and the function derived from all training samples.

Does anyone know an example that they can share? Any help would be greatly appreciated.

First, a definition, which is basically what you said but refers to elements in the domain of the function: "A learning algorithm has high variance for a particular input x if it predicts different output values when trained on different training sets." So, in order to have zero variance, the machine/NN must output the exact same value for x across training sets. The only way to achieve zero variance with respect to all possible x is if you have a constant (non-learning) machine/NN (because then it will trivially maintain its output/function), or if you have training samples perfectly sampled from the same (computable in your machine/NN!) function without noise. An example of such training data would be samples consisting of elements (x,y) all sampled from the same linear function. However, in most real world applications this won't be the case. Furthermore, it isn't necessarily advisable to minimise variance because you will overgeneralize (assume a function for the underlying distribution that is too simple).

Source:

S. Geman, E. Bienenstock, and R. Doursat (1992). Neural networks and the bias/variance dilemma. Neural Computation 4, 1–58.


Repeating a rumor that you started? I've heard that repeating a rumor by denying it only serves to reinforce the rumor.

https://www.linkedin.com/pulse/20141110142443-1967426-how-firms-should-fight-rumors/

Try to avoid reinforcing minor rumors by repeating them in order to deny them.

https://www.psychologytoday.com/us/articles/200811/the-8-laws-rumor-spread

Even a denial can be a repetition of a rumor." (Just ask Senator John Kerry, whose 2004 presidential bid sunk thanks to whispers about his swift-boat service in Vietnam—even though most of the media stories were about how the rumors were false.)

https://www.wikihow.com/Stop-Rumors

If it was you who started the rumor in the first place, don't deny it. Instead of reacting to what others will think of you, admit what you did wrong out of character.

But what about in cases where I told something about myself that was less than flattering, or even downright embarrassing, and am now regretting having said? Does the same principle -- repeat it in any way by denying, asking to keep silent about the matter etc... -- result in heightening the possibility that it will spread to other people, because of the effects of priming?

Or is it the case that if I ask him/her specifically to not repeat the rumor, that he/she will more likely comply compared to if I kept silent about the matter?

The Truth Effect:

  Repetition makes statements easier to process relative to new,
  unrepeated, statements, leading people to believe that the repeated
  conclusion is more truthful. ... The illusory truth effect plays a
  significant role in such fields as election campaigns, advertising,
  news media, and political propaganda.

A seminal experiment is Begg et al (1992), in which subjects were presented with statements that they were told were false, but later rated them as truer than statements they were not previously exposed to.  Merely being exposed to statements makes them more familiar, and hence judged more true, and even being told that they are false does not counteract this effect of familiarity.

More recent studies have replicated these results with fake news stories.  For example, Polage (2012):

  ... repeating false claims will not only increase their believability
  but may also result in source monitoring errors.

And Pennycook et al (2017):

  ... even a single exposure increases subsequent perceptions of
  accuracy ... Moreover, this “illusory truth effect” for fake news
  headlines occurs despite a low level of overall believability, and
  even when the stories are labeled as contested by fact-checkers or are
  inconsistent with the reader’s political ideology. These results
  suggest ... that tagging such stories as disputed is not an effective
  solution to this problem.

This is consistent with belief perseverance.  The broader familiarity effect that causes illusion of truth is called processing fluency or cognitive ease.


What are the key dates for the development of operant conditioning? I am trying to build up a timeline of the development of operant conditioning. So far I have the following

$1898$ - Thorndike performs experiments using his puzzle box of which Skinner based his work on.
$1930$ - Skinner invents a similiar box called the "Skinner box" while studying as a graduate student.
$1938$ - Skinner coins the term "operant conditioning".
$1947$ - Skinner performs experiments on pigeons.
$1948$ - Skinner performs experiments on rats.

However, this timeline leaves me skeptical for two reasons.

The first is that the timeline is very stretched out. Skinner invented the box and then it took him 17-18 years to publish his famous studies. What experiments was he performing with his box that weren't as groundbreaking in all those years when his groundbreaking results features a very basic setup?

The second is that Skinner apparently swapped from rats to pigeons in his experiments because they lived longer, learnt faster and were easier to handle yet the according to my timeline the rats experiment took place after the pigeon one (or perhaps not and he just published them in that order).

I suspect my timeline is not quite right (afterall my references are random internet links). My question is what are the (correct) key dates of the development of operant conditioning? Key dates being the events I have highlighted above and any others you think I have missed. I had more references but unfortunately I can only post 2 links due to my reputation.

It would have been pretty strange for there to be multi-year gaps in Skinner's publication record, and in fact, Skinner continued to publish every year in both of those periods and beyond (Epstein, 1977). I've provided a link to a list of his publications which includes both periods, but there is no real way to say which of these publications were the 'key' studies for operant conditioning. Hopefully, this will still be of some help.

References

Epstein, R. (1977). A listing of the published works of BF Skinner, with notes and comments. Behaviorism, 99-110.


Is Golden Ratio's association with perceived beauty a myth? Many people advocate using the Golden Ratio in design (e.g. logo design).

Is the Golden Ratio's purported aesthetic appeal supported by scientific evidence?

I found a little discussion of the issue in Russell (2000), where he summarises some of the views of the scientific literature:

  Recent reviews of the empirical literature bearing on the claim of
  special aesthetic significance for this ratio in the context of the
  perception of simple figures include Green (1995), Hoge (1995), and
  contributors to a dedicated edition of Empirical Studies of the Arts
  (Hoge 1997). Some investigators doubt that the golden section has any
  aesthetic significance, even suggesting that research on it be
  abandoned (Boselie 1992, 1997; Davis and Jahnke 1991). Others prefer
  to leave the question open, especially in view of the methodological
  difficulties associated with testing the significance of the golden
  section (Green 1995).

Green (1995) argues that "[t]here seems to be, in fact, real psychological effects associated with the golden section, but they are relatively sensitive to careless methodological practices."

Russel (2000) explored the height to width ratio of a large database of famous paintings and did not find any particular support for a preference for the golden-section. Russel suggests that in the real world functional factors tend to constrain ratios.

McManus (1980, PDF) provides an interesting discussion of the methodological issues and the findings of research that has empirically studied aesthetic judgements of simple figures. McManus advocates the use of the paired-comparison method whereby participants make aesthetic judgements on which of series of pairs of objects is more aesthetically attractive. McManus observed that there were substantial individual differences in such preferences. McManus felt that existing empirical research was unable to adequately differentiate preference for the golden-section versus other similar ratios such as 1.5, 1.6 or 1.75.

References

Boselie F, 1992. "The golden section has no special aesthetic attractivity!" Empirical Studies of the Arts 10 1-18.
Boselie F, 1997 "The golden section and the shape of objects" Empirical Studies of the Arts 15 131-141.
Davis S T, Jahnke J C, 1991 "Unity and the golden section: Rules for aesthetic choice?" American Journal of Psychology 104 257 ^ 277
Green C D, 1995 "All that glitters: a review of psychological research on the aesthetics of the
golden section" Perception 24 937-968
Hoge H, 1995 "Fechner's experimental aesthetics and the golden section hypothesis today" Empirical
Studies of the Arts 13 131-148.
Hoge H, 1997 "Why a special issue on the golden section hypothesis? An introduction" Empirical
Studies of the Arts 15 111-114
Russell, P.A. (2000). Testing the aesthetic significance of the golden-section rectangle. PERCEPTION-LONDON-, 29, 1413-1422.
McManus, IC (1980). The aesthetics of simple figures. British Journal of Psychology, 71, 505-524. PDF


How addictive is Heroine? I keep hearing that "*Heroine is so addictive the very first dose is enough to get you hooked on it*".

Personally, I have a hard time believing any substance could do that to you.
But I could believe people spreading that idea to discourage people from consuming it.

Now obviously, I have zero desire to test that hypothesis myself. :P

Still, I'm curious. Does anybody know papers that shed some light on this matter?

"The United Nations World Drug Report 2013 estimated that approximately 16.5 million people worldwide aged 15 or older used heroin or opium. Of these users, approximately 23% are estimated to develop opioid dependence."

This is from the introduction section of Hser, Y. I., Evans, E., Grella, C., Ling, W., & Anglin, D. (2015). Long-term course of opioid addiction. Harvard review of psychiatry, 23(2), 76-89.

They cite:
United Nations Office on Drug and Crime. World drug report 2013. Vienna: UNODC, 2013.

&

Anthony JC, Warner LA, Kessler RC. Comparative epidemiology of dependence on tobacco, alcohol, controlled substances, and inhalants: basic findings from the National Comorbidity Survey. Exp Clin Psychopharmacol 1994; 2: 244–68.

There are various factors that push that probability up or down, sex, age, personality factors, circumstantial factors, some people would have a higher probability, some lower. But the base-rate probability is roughly 1 in 4. For perspective, it's worse odds than Russian roulette (1 in 6), but better odds than unprotected sex leading to an unplanned pregnancy (somewhere around 1 in 3, depending on various things). If you're comfortable with the folk-wisdom of either "Russian roulette will kill you" or "sex leads to pregnancy" you should also be comfortable with the statement "heroin will get you hooked". Sure, they're all approximations, but not terribly misleading ones.


What is the name of the survey question style that forces a choice between non-opposite pairs of items, and why is it used? I've seen personality tests and industrial / organizational psychology tests that force one to choose between non-opposing concepts. What is the name of this question style, and what are the reasons to use it over a more standard question style that forces you to choose between opposing pairs?

Example questions:

In general, I prefer [Assertiveness / Clear communication]

I prefer my direct reports to be [Self-directed / Punctual]

Short answer
Forced-choice task

Background
You have answered your own question:

  ...tests that force one to choose...

Such tests are generally referred to as forced-choice tests in psychophysics. There are many applications of these tests. In general, AFC tasks are less biased than for example yes/no tasks (Yushurun et al, 2008). A sample paper on an AFC test for personality testing is Christiansen et al. (2005).

References
- Christiansen et al. Human Performance (2005); 18(3): 267-307
-  yushurun et al. Vis Res (2008); 48(17): 1837-51


Are we actually seeing black colored objects? We know that black objects absorb light with almost all the frequencies of the visible spectrum. This means there will not be any frequency of light reflected and falling on our retina, in order for us to see that object.

Does this mean that I am actually not seeing the black object but differentiating it from the surrounding?

Actually, black objects absorb light across visible frequencies indiscriminately, but not completely. So some light still reflects off them. This is described on this Q&A of the Department of Physics, University of Illinois at Urbana-Champaign.

But even if there was a perfectly black objects which absorbs 100% of the light that falls on it, you could still perceive it as it via the contrast to other objects around it.


Why are people better at distinguishing people of their own racial group and why are animals better at recognising animals of their own species? Why can certain people only recognize certain people. For example, if someone white sees a bunch of African or Asian people, how come it's hard for him to differentiate between them, while they can differentiate between themselves so easily. And the same thing with animals, for example: how come apes can differentiate between themselves, but when I go to the zoo they all look the same. Also since facial recognition is not a thing from the past anymore, does anyone know how much are faces really are different?

The ability of people to better recognise and distinguish faces of their own race has been well studied.

For a general discussion, see Cross-race effect where a range of hypotheses have been proposed.


Impact of the first love experience When we become adults, we think that love is for adults only associating it with sexual relations but I'm sure that all of us have loved or have had some admiration for the daughter of the neighborhood or a girl attending the same school: that's an idyllic love, I'm sure.

If we know that childhood is characterized by a strong learning capacities and that the learned experiences will have a strong impact on the future behavior of the child, thus the future man or woman, can someone accept easily to see the girl(for a man) or the boy(for a girl) that he/she  dreamt in married with another one (when he begins his adulthood).

Isn't such a heart-breaking experience, that can prevent our mind from trying to build new relationships (since we can not replace, at least in our mind,the representation of the loved one while it's becoming a nightmare in the same time)?

And when our mind survive this chaos, will he seek to find someone  resembling the one loved during childhood without that we even notice?

How is it that people overcome the initial pain of failed love to feel brave enough to risk such pain again when starting relationships?
Do people tend to look for someone who reminds them of their first love?
Is there any studies or statistics for married couples that were "in love" since childhood?

This answer reflects my own thoughts on this topic, It isn't any generalized opinion of psychologists that I am putting forth.

First:- Each person is indispensable (not just the one we love), comes with his own characteristics, teaches us to look at the world from different perspective. But we notice the impact of the one we love more than any other because we want to feel how he looks at the world, how he feels.

We want to feel how it is to be him? Therefore his characteristics become our characteristics (to an extent). Some people say that you become a person you are in love with. Now he has abandoned you, you miss him more and more because some part of him is still in you.

Failed love empties our world and induces a void within life. If given a chance to pinpoint the worst feeling related with failed love and longing for it, I would say that it's the vacuum that haunts us after the person we love doesn't accept us.

Therefore, trying to move on must be acknowledged as our attempt to fill that vacuum. Of course, by doing so we run the risk of being abandoned again. But that is small compared to our desire to fulfill our love, to fill that void.

Second:- Whether or not we look for someone who reminds us of the person we love is another paradigm of our love history.

How acrimonious the breakup was?
What stage of love were we at when this happened? Because more the time, more difficult will be to give up on the one you love
Who according to us was responsible for the breakup?
How dedicated we were in that relationship?

If a person thinks that he was responsible for the breakup, definitely he would search for someone with similar characteristics and once he finds one, he'd be conscious this time and wouldn't try to repeat his mistakes in this new relationship.

If he holds the other person responsible for the breakup, then it is difficult to try to accept some other person with same characteristics.

Third:- Really, I can't comment on this third one.


Phenomena where group truly feels a certain way, but each member says that they feel the other way to avoid being the odd one out I forgot the name, but I remember reading about it in lifehacker or i09 some time ago.

When the group feels a certain way, but say that they feel the other way to avoid being the only one to agree. Despite all of them feeling the same way.

For example, a group goes to a restaurant. All of them hate the food. But no one wants to be the one to say it, so they all unwittingly say it's great and that they are enjoying.

I believe the name you are searching for is conformity.

One of the most well-known examples: Asch Conformity Experiments.


What is a realistic mathematical function to model link decay in a social network? I'm wondering (as a non-psychologist/cogsci programmer) what would be a good mathematical function to model the decay human relationships, or in other words, how people forget about people they don't interact anymore.

The background: I'm building an agent-based model where agents (representing people) interact, converging on a semi-stable network. If a link between two agents is not used, it should weaken, and eventually fade. Currently the growth and decay of a link between two agents is linear between 0..1 (more interactions -> stronger link, up to 1; less interactions -> link gradually weakens, evetually drops to 0). While my current decay function is linear, for the part that controls who interacts with who, I'm using an S-shaped function - there's a higher chance to interact with agents one knows, and who their "friends" know, but the sum of these values is then "bent" on an S-curve.

The concept of time in the model (counted in iterations of interactions) is relative, so it's not about minutes, days or years. I'm rather interested in a formal model that would capture the dynamics of forgetting people they don't see around anymore. I have a gut feeling it's not linear - one won't start to forget their mother, and the relationship won't weaken, if they don't see her for a little while. But if you just ask for directions on the street, chances are you'll forget the person rather quickly (unless he/she was hot or something; but the agents in my model don't have properties pertaining to such attributes).

A few alternatives could thus be: a sigmoid/S-curve (but the "steepness/curviness" would be a question still; green line below), logarithmic (also looks nice, but steepness of the curve would be a question; yellow), exponential (doesn't seem likely though; orange), perfect memory until arbitrary cutoff (probably not; red), compared to simply linear (blue).

If an curve could be decided on for the decay, then I suppose I would also use it for link growth (e.g., on an S-curve a slow growth in the beginning up to a point (strangers) and towards higher values (friends past the get-to-know phase)). It might be useful to think of the lines on the plot as trajectories of a relationship, with the stength on the y-axis and relative time (either way) on x.

The question then: which one of these functions (and which parameters; or some other function) would be best to model the dynamics of how quickly people start to forget about/lose their connections with other people when they don't interact - or in other words, how a relationship weakens due to sparse contact? I assume there's literature on the subject, but I would have no idea where to start (googling generic keywords like relationships and decay function does not help), so a good answer could cite relevant sources or otherwise show the superiority of one function over the others.

Here's a nice paper that explores the question in depth: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4626528/. The authors measure the emotional closeness as frequency of contact and number of different activities done together for a group of 25 people over the period of 18 months. As far as I can tell from the charts, the decay curve is closer to an exponent than to anything else for friends. However, for the kin the emotional closeness increases over time - though, again, in an exponential way.


Success rates or reviews of Brain Working Recursive Therapy (BWRT), and number of sessions needed on average Brain Working Recursive Therapy (BWRT), introduced by hypnotherapist Terrence Watts in 2011, is a brand new form of therapy. Hence, my internet search doesn't seem to give me any idea of how successful it really is. Here's a link to the official page of BWRT: https://www.bwrt.org/. It hasn't got a wikipidea page yet.

How many sessions of BWRT does one need in general to cure one specific problem?

If you could cite any links or even your personal experience, I'd greatly appreciate it!

Looking at the client testimonials on the website you provided it looks like it varies from 1 session to a few more.  Like any other therapy it seems to depend on the client and problem being dealt with.

You could ask the therapist how many sessions you are likely to need for your problem in order to find out whether you would like to go ahead or not.

I am really interested in this and I am going to look at this therapy in some detail as it is interesting to me considering it is supposedly not a remodel of NLP, EFT, TFT, WSN, SD, EMDR, Hypnosis, Reiki, Meridian/Energy therapies, Noesiology, Chinosis or any other style of therapy according to the home page.


is it possible to think without language? I'm trying to fathom what it might be like for a person with aphasia and for one with agnosia. For a person with a visual agnosia I wonder this: if two unrecognizable objects are shown to them, and one is entirely within the background of the other, (say a fork on a cutting board) do these two objects mold into a single unrecognizable object or do they remain distinct unrecognizable objects? Or have I got it all wrong and they don't even "see" any object to speak of (regardless of how many or how they are positioned)?

I think the answer is a qualified yes, humans can think without language. Ultimately though it depends on what you mean by "think."

There is a remarkably large number of deaf people who are not exposed either to a signed or spoken language even in developed countries. These people often invent their own gesture systems, referred to as home sign systems. These people  In these cases, the deaf children's systems are more complex than the gestures their parents use (Carrigan & Coppola, 2012). My dad was a home signer until after high school, and he learned how to work on his car, drove a motorcycle, and figured out how the furnace worked. Based on these examples, it is clearly possible to engage in fairly complex reasoning without language. In the article cited below, Spaepen et al. (2011) describe how home signers have some concept of number, albeit imprecise.

This is all to say that thinking is possible without language. Home signers are not catatonic, and can actually engage in complex reasoning. One the other hand, language is a huge cognitive advantage, and in this respect it certainly has an impact on thinking. Language facilitates transmission of information (learning), and it provides a way of organizing thought.

Carrigan, E. M., & Coppola, M. (2012). Mothers Do Not Drive Structure in Adult Homesign Systems: Evidence from Comprehension. In N. Miyake, D. Peebles, & RP Cooper,(Eds.), Proceedings of the 34th Annual Conference of the Cognitive Science Society (pp. 1398-1403).

Spaepen, E., Coppola, M., Spelke, E. S., Carey, S. E., & Goldin-Meadow, S. (2011). Number without a language model. Proceedings of the National Academy of Sciences, 108(8), 3163-3168.


What is the effect of Social Media consumption on self-esteem? I have been seeing many conflicting studies saying that facebook usage increases or decreases self-esteem.

What is the current consensus regarding the effect of facebook usage on self-esteem?
Has there been a meta-analysis?

I can see that looking at facebook would make one compare himself to another (upward comparison). This could induce jealousy. Likewise, seeing your own facebook profile reaffirms who you are. This would increase self esteem.

In general social media is a positive inlet for self-esteem development. As people "like" the things you like your identity is reaffirmed. However if someone friend's the wrong people or uses it as a comparison engine it can become degrading to self-esteem. It should be noted that teenagers are trending away from traditional social networking moving to things like SnapChat.

  The aim of this study was to investigate the consequences of friend networking sites (e.g., Friendster, MySpace) for adolescents' self-esteem and well-being. We conducted a survey among 881 adolescents (10–19-year-olds) who had an online profile on a Dutch friend networking site. Using structural equation modeling, we found that the frequency with which adolescents used the site had an indirect effect on their social self-esteem and well-being. The use of the friend networking site stimulated the number of relationships formed on the site, the frequency with which adolescents received feedback on their profiles, and the tone (i.e., positive vs. negative) of this feedback. Positive feedback on the profiles enhanced adolescents' social self-esteem and well-being, whereas negative feedback decreased their selfesteem and well-being.

-Friend Networking Sites and Their Relationship to Adolescents' Well-Being and Social Self-Esteem

  This study assessed motives for social network site (SNS) use, group belonging, collective self-esteem, and gender effects among older adolescents. Communication with peer group members was the most important motivation for SNS use. Participants high in positive collective self-esteem were strongly motivated to communicate with peer group via SNS. Females were more likely to report high positive collective self-esteem, greater overall use, and SNS use to communicate with peers. Females also posted higher means for group-in-self, passing time, and entertainment. Negative collective self-esteem correlated with social compensation, suggesting that those who felt negatively about their social group used SNS as an alternative to communicating with other group members. Males were more likely than females to report negative collective self-esteem and SNS use for social compensation and social identity gratifications.

-Older Adolescents' Motivations for Social Network Site Use: The Influence of Gender, Group Identity, and Collective Self-Esteem


What is the correlation between self-rated and objective measures of intelligence? In the context of a broader question, someone asked:

  Can the detailed analyses from, say, the Wechsler test, be used to inform decisions significantly better that gut feelings can?

While this question might be closed, I thought a more defined question regarding the correlation between self-rated and objective measures of intelligence would be good to have. I feel as if I've read papers that suggest the correlation is modest (e.g., r = .2 or .3). Presumably, Dunning-Kruger and a bunch of self-serving biases operate. But I could not find any authoritative reference off hand. So my questions:

What is the correlation between self-rated intelligence and objective measures of intelligence (i.e., full scale IQ scores from well-validated measures)?
To what extent does the correlation depend on how the self-ratings are obtained?

The term you are looking for is self-assessed intelligence (SAI) (sometimes subjectively-assessed intelligence or self-estimated intelligence).  The leaders in this field are Tomas Chamorro-Premuzic and Adrian Furnham.  From their book "Personality and Intellectual Competence" (2014):

  Correlations between SAI and psychometric intelligence have been
  significant and positive, albeit generally modest (r<.30).

So you are spot on. :-) SAI is a subset of self-tests of intelligence, that can range from simple estimates, to full-fledged self-administered IQ tests.  As such, correlations can vary a lot.  However, SAI is generally considered to be an estimate, rather than a test, and this does not appear to be affected much by methodology.  From Paulhus et al (1998):

  Correlations between single-item self-reports of intelligence and IQ
  scores are rather low (.20–.25) in college samples. The literature
  suggested that self-reports could be improved by three strategies: (1)
  aggregation, (2)item weighting, and (3) use of indirect, rather than
  direct, questions. ... Although results showed some success for both
  direct and indirect measures, the failure of their validities to
  exceed .30 impugns their utility as IQ proxies in competitive college
  samples.

On the other hand, the SAI literature reveals significant gender differences in SAI estimates - with males significantly overestimating and females significantly underestimating their intelligence - as well as significant cross-cultural differences in estimates, suggesting that the correlation is more heavily affected by social stereotypes.


Source for standardized audio files for an experiment in German I need some audio files for an experiment. In this experiment, numbers will be played to the subjects via headphones, so I need sound files with spoken numbers. Actually, a single file with a sequence of numbers is fine.

The goal is to produce a similar experiment as the one by Neil W. Mulligan (The Role of Attention During Encoding in Implicit and Explicit Memory). In this experiment, the material from the test set developed by Blaxton (1989) were used.

Is there any standardized database for this kind of things? I know there are standardized face databases, but I am not sure about sound files and googling did not help.

The problem is that the subjects will be from Germany, so I need the numbers in German.

Try this:

http://translate.google.com/translate_tts?tl=de&q="1"

or this:

http://translate.google.com/translate_tts?tl=de&q="11;27;39;81;32;53"

At the moment, I can't test if it pronounces the full numbers right, but I hope it will work.

I think the pronunciation of higher numbers are better if you write them like this: NineHundredSixtySix


Term for emotional distancing? Is there a medical/psychological term for changing one's vantage from 1st person to 3rd person?
An example would be focusing one's eyes on an object while working out to partly  distract them from the pain – changing vantage from participant to observer.
I have heard this called 'emotional distancing' but it would seem such an important skill that I ask if there is a more formal term.

The term you are looking for is illeism: the tendency in some individuals to refer to themselves in the third person. It can be used as a literary device, but it is used to refer to when real people change vantage point and - through a mental condition or social context - refer to themselves in the third person, possibly after referring to themselves in the first person.


Is there a biological limit for "amount" of happiness? I have heard about neurotransmitters like dopamin and serotonin that are supposed to play a role in our feeling of happiness. I don't know how these chemicals works in our brain, but I am thinking that if happiness is dependent on chemical reactions in our brains there must be some physical limit to how happy we can be.

If I own a 10 million dollar yacht, and upgrade to a 100 million dollar yacht could it be that my happiness is already at its maximum and I am throwing away 90 million dollars?

Does the chemistry of the brain impose a limit on how happy it is possible to feel?

My knowledge of the neurobiology of pleasure (aka, hedonia, hedonic happiness, happiness, "liking", reward, etc.) is admittedly lacking, but I'd contend that this is mostly true because we actually know very little about how pleasure is instantiated in the brain.  So the answer to your question is that we don't know!

First of all, mesolimbic dopamine seems to be more involved in the motivational component of reward (what Berridge and Kringelbach would call "wanting"; e.g., Kringelbach & Berridge, 2009; see also Salamone & Correa, 2012).

On the other hand, opioid and cannabinoid neurotransmitter signals (and others) seem to mediate the hedonic component (i.e., the "liking"). Even then, stimulation only to certain parts of the brain (i.e., "hotspots") produce hedonia (e.g., in parts of the nucleus accumbens; Pecina, Smith, & Berridge, 2006).  And even then, as the context changes, these hotspots will stop producing the expected output or will change valence.  And even then, these findings from non-human animals may not be comparable to the more complex experiences of pleasure that humans have!

And only very recently have we been able to map out which brain regions correspond to positive or negative affect (Lindquist et al., 2015).  And it seems that no brain region or voxel uniquely represents positive or negative affect (see degeneracy). (But there are preferences. And there may be confusion between which regions cause pleasure and which code pleasure; Kringelbach & Berridge, 2009).

Not to mention, happiness encompasses a broad range of potentially heterogeneous experiences and feelings.  Happiness evoked by one experience might feel very different and look very different in the brain compared to some other happy experience (see C. Wilson-Mendenhall's work).  So how do we compare?

And this is just the broader view.  How the biochemistry of the brain produces the subjective experience of pleasure is completely unknown, so it's more or less impossible to know (at present) whether there's a biological limit to the intensity of happiness.


How do brain zaps occur? I've recently witnessed someone undergoing brain zaps and subsequent panic attacks after having stopped their SSRI medication and 48 hours partying with heavy boozing and no sleep.

Having reviewed the literature, I'm under the impression that they often occur in stress related situations or serotonin dysregulation (MDMA seems to trigger brain zaps), but I also read isolated people claiming they could voluntarily trigger brain zaps by "tensing up" and voluntary eye movements. These people said they could do that in a context devoid of any anxiety issues. Also a few marginal reports of brain zaps by heavy opiate, LSD, DXM and ketamin users, but who do not seem specific about details.

I'm under the impression that brain zaps can be caused by anxiety, but also that they can trigger violent panic attacks (fight-or-flight response from the brain zaps), but again also that they reportedly occur in the absence of stress.

What is known of what really happens at a cognitive, neural, or psychochemical level during brain zaps? What's the mechanisms? In the absence of hard science about it, what are the most plausible speculations?

Here's the only speculation I could find about brain shivers aka brain zaps.

Cortes JA, Radhakrishnan R. A Case of Amelioration of Venlafaxine-Discontinuation “Brain Shivers” With Atomoxetine The Primary Care Companion for CNS Disorders. 2013;15(2):PCC.12l01427. doi:10.4088/PCC.12l01427.

It proposes an explanation related to norepinephrine. Also, it claims that brain shivers or brain zaps are related to Lhermitte's phenomenon. I have mixed feelings about this specific comparison from what I've witnessed.

"These facts point to the possibility that increases in synaptic norepinephrine are due to norepinephrine transporter reversal, akin to dopamine transporter reversal associated with amphetamine. Abrupt withdrawal of venlafaxine would hence result in paradoxical increase in synaptic norepinephrine via efflux through norepinephrine transporter channels, which is normalized by atomoxetine’s norepinephrine transporter blockade."

That would explain brain zaps from stopping tramadol and SNRIs too, by the way: a noradrenergic syndrome.

Anyone has a better or more supported speculation?


What are the predominant cognitive effects that influence textual learning and recall? I am a rulebook writer and editor, and I have been digging into the literature for cognitive effects and heuristics that affect one's ability to learn and remember complicated concepts from text. For example, the primacy effect and recency effect show that it's easier to recall information stated at the beginning and end of a list.

What are some other predominant cognitive effects or heuristics that affect learning and recall from text?

Both the primacy and recency effects may also be referred to as parts of the serial position effect. Wikipedia has a list of memory biases you may want to peruse. Most entries are potentially relevant:

  Cryptomnesia: a form of misattribution where a memory is mistaken for imagination, because there is no subjective experience of it being a memory.[1][See misattribution of memory.]
  Egocentric bias: recalling the past in a self-serving manner, e.g., remembering one's exam grades as being better than they were...
  Fading affect bias: a bias in which the emotion associated with unpleasant memories fades more quickly than the emotion associated with positive events.[4]...
  Google effect: the tendency to forget information that can be easily found online...
  Humor effect: that humorous items are more easily remembered than non-humorous ones, which might be explained by the distinctiveness of humor, the increased cognitive processing time to understand the humor, or the emotional arousal caused by the humor...
  Leveling and Sharpening: memory distortions introduced by the loss of details in a recollection over time, often concurrent with sharpening or selective recollection of certain details that take on exaggerated significance in relation to the details or aspects of the experience lost through leveling. Both biases may be reinforced over time, and by repeated recollection or re-telling of a memory.[6]
  Levels-of-processing effect: that different methods of encoding information into memory have different levels of effectiveness (Craik & Lockhart, 1972).
  List-length effect: a smaller percentage of items are remembered in a longer list, but as the length of the list increases, the absolute number of items remembered increases as well...
  Misattribution of memory: when information is retained in memory but the source of the memory is forgotten. One of Schacter's (1999) Seven Sins of Memory, Misattribution was divided into Source Confusion, Cryptomnesia and False Recall/False Recognition.[1]
  Memory inhibition: that being shown some items from a list makes it harder to retrieve the other items (e.g., Slamecka, 1968).
  Modality effect: that memory recall is higher for the last items of a list when the list items were received via speech than when they were received via writing.
  Mood congruent memory bias: the improved recall of information congruent with one's current mood...
  Peak-end effect: that people seem to perceive not the sum of an experience but the average of how it was at its peak (e.g. pleasant or unpleasant) and how it ended...
  Picture superiority effect: that concepts are much more likely to be remembered experientially if they are presented in picture form than if they are presented in word form.[7]...
  Positivity effect: that older adults favor positive over negative information in their memories.
  Primacy effect, Recency effect & Serial position effect:[10] that items near the end of a list are the easiest to recall, followed by the items at the beginning of a list; items in the middle are the least likely to be remembered.[10]...
  Rosy retrospection: the remembering of the past as having been better than it really was.
  Self-reference effect: the phenomena that memories encoded with relation to the self are better recalled than similar information encoded otherwise...
  Source Confusion: [Omitted; redundant with misattribution of memory.]
  Spacing effect: that information is better recalled if exposure to it is repeated over a longer span of time. [Also mentioned as "lag effect".]
  Stereotypical bias: memory distorted towards stereotypes (e.g. racial or gender), e.g. "black-sounding" names being misremembered as names of criminals.[1]
  Suffix effect: the weakening of the recency effect in the case that an item is appended to the list that the subject is not required to recall (Morton, Crowder & Prussin, 1971)...
  Testing effect: that frequent testing of material that has been committed to memory improves memory recall.
  Tip of the tongue: when a subject is able to recall parts of an item, or related information, but is frustratingly unable to recall the whole item. This is thought to be an instance of "blocking" where multiple similar memories are being recalled and interfere with each other.[1]
  Verbatim effect: that the "gist" of what someone has said is better remembered than the verbatim wording (Poppenk, Walia, Joanisse, Danckert, & Köhler, 2006).
  Von Restorff effect: that an item that sticks out is more likely to be remembered than other items (von Restorff, 1933).
  Zeigarnik effect: that uncompleted or interrupted tasks are remembered better than completed ones.

I've reproduced most of the list, because most could apply for one kind of written material or another (e.g., novels, textbooks, one's own work). I've noted a few redundancies in brackets, but I may have missed others. I've also embedded a few extra hyperlinks to original sources where freely available.

References
1. Schacter, D. L. (1999). The seven sins of memory: Insights from psychology and cognitive neuroscience. American Psychologist, 54(3), 182–203. Retrieved from http://nwkpsych.rutgers.edu/~jose/courses/578_mem_learn/2012/readings/Schacter_1999.pdf.
4. Walker, W. R., Skowronski, J. J., & Thompson, C. P. (2003). Life is pleasant—and memory helps to keep it that way! Review of General Psychology, 7(2), 203–210. Retrieved from http://goo.gl/zs179s.
6. Koriat, A., Goldsmith, M., & Pansky, A. (2000). Toward a psychology of memory accuracy. Annual Review of Psychology, 51(1), 481–537. Retrieved from http://academic.udayton.edu/SusanDavis/PSY%20522/Articles/Towards%20a%20psychology%20of%20memory%20accuracy.pdf.
7. Nelson, D. L., Reed, V. S., & Walling, J. R. (1976). Pictorial superiority effect. Journal of Experimental Psychology: Human Learning and Memory, 2(5), 523–528.
10. Martin, G. N., Carlson, N. R., & Buskist, W. (2007). Psychology (3rd ed., pp. 309–310). Pearson Education.

- Craik, F. I., & Lockhart, R. S. (1972). Levels of processing: A framework for memory research. Journal of Verbal Learning and Verbal Behavior, 11(6), 671–684. Retrieved from http://www.numyspace.co.uk/~unn_tsmc4/prac/labs/depth/craiklock.pdf.
- Morton, J., Crowder, R. G., & Prussin, H. A. (1971). Experiments with the stimulus suffix effect. Journal of Experimental Psychology, 91(1), 169–190.
- Poppenk, J., Walia, G., Joanisse, M., Danckert, S., & Köhler, S. (2006). Why is form
information in sentences poorly remembered? An fMRI study on the role of
novelty-encoding processes. Supplement of the Journal of Cognitive
Neuroscience, 18, (Paper presented at the 13th Annual Meeting of the Cognitive
Neuroscience Society, San Francisco, California, USA).
- Slamecka, N. J. (1968). An examination of trace storage in free recall. Journal of Experimental Psychology, 76(4), 504–513. Retrieved from http://www.tamu.edu/faculty/stevesmith/689/Inhibition/Slamecka%201968.pdf.
- Von Restorff, H. (1933). Über die wirkung von bereichsbildungen im spurenfeld. Psychologische Forschung, 18(1), 299–342.


Why do people fear ghosts but not believe in fairies? I don't have any data to back this up, but it seems people are quick to question their non-belief in the horror side of the supernatural (while in dark rooms and the like), but still scoff at the idea of magic, and other fictional tropes. Even if the person knows perfectly well that ghosts don't exist, why does that particular myth prove hard to dispel?
I'm new to this site, so I apologise if it's not an appropriate question here.

There are some arguments for the origins of religion based on the byproducts of our adaptive cognitive mechanisms and biases. A prominent one is the hyperactive agency detection device (HADD)--we are quick to infer the presence of intentional agency upon hearing a sudden unexplained noise or unnatural movement, especially in low perceptual quality situations (e.g. the dark). The cultural description of ghosts and other feared supernatural entities align with the situations in which HADD is likely to be triggered, but not so much fairies.


Is there any science behind movie/commercial camera angle changes? Most of the regular waking cognition experiences a continuous visual field. One object of focus flows into another. Objects out of focus are pushed to the periphery. A person may move one's view around in a 360 degree sphere, but from a single point in space. For example, moving eyes away from the monitor towards the desk keeps the monitor in the field of view, just moves it to the periphery.

Now, as I'm looking at modern day (2012) movies and commercials, I notice that a lot of them feature abrupt changes from one image to another, from one camera angle to another. It is as if the perspective shifts about in space.

Quite a lot of these image changes are very brief - just a few seconds long. For example, a conversation on screen may have camera on one actor talking, then jump to show the other actor's reaction, then snap back. Commercials are even worse - if viewed out of the corner of one's eye, they frequently appear as just a series of flashes.

I'm interested if there's any science behind these abrupt changes in camera angles and flashes of images. For example, I know that a human eye needs about 25 frames per second to perceive fluid motion on the screen. A refresh rate of 60 hertz is the minimum to avoid eye strain. Are there any similar numbers related to the duration of exposure to the stimulus, for example(fake numbers):

0.75 seconds to capture emotion on the human's face
2 seconds to comprehend action (ex: car driving on screen)
3 seconds flash of explosion is enough to produce excitement
14 seconds to become familiar with the scene

Admittedly, this question has intrigued me also.  This is a partial answer, as the article below deals with perceptions borne of camera angles of a person, as an example of the effect of camera angles.

According to the article "The influence of camera angle on comprehension and retention of pictorial events" (Kraft, 1987), camera angles significantly influence viewers' mental construct of the story representations.  These representations are related to our experience with the real world around us.

Kraft summarises previous research in saying that there is a connotation that:

  physically looking down at an actor
  translates into looking down on that actor; physically looking
  up at an actor translates into looking up to that actor.

This also could apply to characters.  Thus influencing our perception of the person and the events surrounding them.

In regards to scenes:

  by changing vertical camera angle, one changes the real life
  consequences of the pictured scene.

These connotations are often 'woven into the storyline'.

I hope this helps


Persuasion strategies by Cialdini (why is punishment not there?) Cialdini is famous for his book "Influence" where he talks about various ways to get people to do things you want them to.  They are:

reciprocation
commitment/consistency
scarcity
authority
liking
social proof

Should not punishment be included?  Or are there soft/hard ways of persuasion, or perhaps short-term/long-term distinction?

I considered maybe punishment is part of authority, but do all forms of authority have additional power to punish?  I don't think so.  Some are just empty titles/positions.  In addition, non-authority figures also have the power to punish, even if it's not legitimized, and as a result an abusive parent or child, or a bully or someone wielding a knife can punish you if you don't do what they say.  In addition, the effects of or threat of punishment itself can also last a long time, like many other persuasion/influence strategies.

Briefly looking at an article summarizing Cialdini's viewpoints ("The Science and Practice of Persuasion", 2001, free pdf; doi link), he does not include threats of punishment under "authority". By "authority", Cialdini means the status of the influencer, such as being recognized as an expert on the subject-matter.
As far as I can tell, in his book, Cialdini barely tackles punishment directly. The most detailed passage dealing with punishment (as a strategy) seems to be one one child rearing, and even this occurs in a footnote:

The occurrence of the Romeo and Juliet effect should not be interpreted
as a warning to parents to be always accepting of their teenagers’
romantic choices. New players at this delicate game are likely to err
often and, consequently, would benefit from the direction of an adult
with greater perspective and experience. In providing such direction,
parents should recognize that teenagers, who see themselves as young
adults, will not respond well to control attempts that are typical of
parent-child relationships. Especially in the clearly adult arena of mating,
adult tools of influence (preference and persuasion) will be more
effective than traditional forms of parental control (prohibitions and
punishments). Although the experience of the Montague and Capulet
families is an extreme example, heavy-handed restrictions on a young
romantic alliance may well turn it clandestine, torrid, and sad.

So he does include punishment at least under "parental control"... which I don't know where exactly it fits in Cialdini's ontology. Cialdini's book is very narrative with a lot of anecdotes, but he does not engage in a lot of systematization (beyond the chapter-level one which you've mentioned in your question). But from that passage he does seem to consider persuasion as not encompassing punishment. This is a fairly purist view, as I further detail below from the (review) perspective of other authors.
You are correct that other authors (in contrast) do consider punishment as form of persuasion, particularly in legal contexts. Quoting the SEP page on legal punishment:

However, an obvious and crucial question faces any such justification of punishment as a communicative enterprise. Censure can be communicated through a formal conviction in a criminal court; or it could be communicated by some further formal denunciation issued by a judge or some other representative of the legal community, or by a system of purely symbolic punishments which were burdensome only in virtue of their censorial meaning. It can, of course, also be communicated by ‘hard treatment’ punishments of the kinds imposed by our courts — by imprisonment, by compulsory community service, by fines and the like, which are burdensome independently of their censorial meaning (on ‘hard treatment’, see Feinberg 1970): but why should we choose such methods of communication, rather than methods that do not involve hard treatment (see Christie 1981: 98–105)? Is it because they will make the communication more effective (see Falls 1987; Primoratz 1989; Kleinig 1991)? But why is it so important to make the communication effective — and is there not a serious danger that the hard treatment will conceal, rather than highlight, the moral censure it should communicate (see Mathiesen 1990: 58–73)?
One sort of answer to this question explains penal hard treatment as an essential aspect of the enterprise of moral communication itself. Punishment, on this view, should aim not merely to communicate censure to the offender, but to persuade the offender to recognise and repent the wrong he has done, and so to recognise the need to reform himself and his future conduct, and to make apologetic reparation to those whom he wronged. His punishment then constitutes a kind of secular penance that he is required to undergo for his crime: its hard treatment aspects, the burden it imposes on him, should serve both to assist the process of repentance and reform, by focusing his attention on his crime and its implications, and as a way of making the apologetic reparation that he owes (see Duff 2001, 2011; see also Garvey 1999, 2003; Tudor 2001; Bennett 2008; for a sophisticated discussion see Tasioulas 2006). This type of account faces serious objections (see Bickenbach 1988; Ten 1990; von Hirsch 1999; Bagaric and Amarasekara 2000; von Hirsch and Ashworth 2005, ch. 7): in particular that it cannot show penal hard treatment to be a necessary aspect of a communicative enterprise which is still to respect offenders as responsible and rational agents who must be left free to remain unpersuaded; that apologetic reparation must be voluntary if it is to be of any real value; and that a liberal state should not take this kind of intrusive interest in its citizens’ moral characters.

From that I gather that it is controversial whether punishment can be considered true persuasion though, i.e. some other authors disagree.
I suspect that in psychological terms, those who argue for punishment as persuasion are behaviorists, in that they don't care what's going on in the mind of the punished as long as the desired outcome (e.g. non reoffending) happens. On the other hand, cognitivists would probably argue that if the outcome does not also include the target internalizing/adopting the viewpoint (that is being communicated) then it is not actual persuasion, but mere compliance-- a sort of machiavellian behavior basically. An exam flashcard says:

What is the difference between persuasion and compliance gaining?
Persuasion is a change in attitudes, beliefs and values whereas compliance gaining is focused on changing behavior, getting someone to do what you want.

That's probably based on some intro 101 book. The research monograph by Seiter and Gass (Perspectives on Persuasion) has a three-page table with definitions of persuasion by various authors... and they don't really agree.  Seiter and Gass have their own view (of course):

Our position is that many of the definitional vagaries can be clarified, if not resolved. by
focusing on two considerations. The first is whether a given scholar or researcher is attempting
to define "pure" persuasion- what Simons (1986) and O'Keefe (1990) have labeled
"paradigm" cases of persuasion-versus all of persuasion, including its periphery.
which we term "borderline" cases of persuasion, By pure persuasion. we refer to clear-cut
cases on which almost all scholars in communication and related disciplines would agree.
As examples. nearly everyone would include a presidential debate, a television commercial.
or an attorney's closing remarks to a jury as instances of persuasion.
Other instances. though, lie closer to the boundary of what we normally think of as
persuasion. Not everyone would agree that a derelict's mere appearance "persuades" passersby
to keep their distance. Nor would everyone agree that when city planners install
speed bumps on a street where speeding is common. they are "persuading" motorists to
slow down. Such cases are less clear-cut. Much of the disparity in definitions. then. is
rooted in the fact that some scholars and researchers are concerned with "pure" persuasion.
whereas others are concerned with borderline cases as well.

Comparing this summary with the passage from Cialdini's book I cited in the beginning, it seems clear enough to me Cialdini was/is preferring (or at least implicitly using) a "pure" definition of persuasion.
Seiter and Gass also have a textbook (with a similar title but less research oriented), which repeats their view form their monographs, augmented with a pretty illustration (well, the illustration is present in the monograph as well):

As you can see the "coercive" form of persuasion, which would include punishment (or at least the threat thereof) is in the borderline bin/area. And in the textbook they further drive that point with a cartoon:

accompanied by an elaboration that coercion and persuasion lie on a continuum, and that pure forms are rarely encountered in everyday life experiences:

we would suggest that  most influence attempts we encounter in daily life include both persuasive and coercive elements. Rarely in life is one free to make a a completely unfettered choice. There are almost always strings attached. This is particularly true of face-to-face encounters. If a  friend asks to borrow 20 bucks, we can say "no," but there may be relational consequences for declining.
Rarely, too, are influence attempts completely coercive. For example, holding a gun to another person's head would seem to be an obvious example of coercion. We readily admit that this situation is primarily coercive. But what if the victim doesn't believe the gun is loaded? Or what if the victim thinks the threatener is bluffing? To be successful, a thread--even a threat of violence--must be perceived as credible. Thus, even in what might see like a clear-cut case of coercion there are persuasive elements at work. And conversely, even in what appear to be cut-and-dried cases of persuasion, there may be coercive features operating. In out view, the isn't so much whether a situation is persuasive or coercive as how persuasive or coercive the situation is. [emphasis in original].


What did Freud intend as the referent of 'Das Es' (Latin: 'id')? Why didn't he name with the referent? Wikipedia states:

  The terms "id", "ego", and "super-ego" are not Freud's own. They are latinisations by his translator James Strachey. Freud himself wrote of "das Es",[5] "das Ich",[19] and "das Über-Ich"[28]—respectively, "the It", "the I", and "the Over-I" (or "I above"); thus to the German reader, Freud's original terms are more or less self-explanatory. [...]

What's the referent of the German pronoun 'Es'?
Why didn't Freud name (the concept known as ⟨Es⟩) with the referent itself instead? I.e., wouldn't naming ⟨Es⟩ as 'Instinkt' to mean 'instinctual drive' make the term easier to understand and more self-explanatory?

Short answer
Freud din't come up with that terminology, he borrowed it from his contemporaries.

Background
According to wikipedia Freud borrowed the term "das Es" from Georg Groddeck, a German physician to whose unconventional ideas Freud was much attracted (Groddeck's translators render the term in English also as "the It").

Nietzsche, who is thought to have influenced Freud also often used the German pronoun das Es. Freud’s English translator indeed used the Latin word 'id'.


What happens in my retina if I press on my eyeballs? If I press my eyes I can "see" all kind of things: sparkling blue dots (which sometimes seem random and sometimes there seems to be a pattern in them), growing or diminishing rings of all kinds of color (I once read that these circles are also present in the retina of the non-yet-born, to provide some preparation), vague black-and-white faces, and many more, sometimes strange, sometimes for a short time recognizable forms.

So, what strange capers are the different light receptors, or neurons in or behind the retinas of my eyes performing?

Short answer
Pressure phosphenes are believed to be induced by sensory neurons in the retina downstream from the photoreceptors due to stretch-mediated activation.

Background
You are referring to pressure phosphenes. They are visual perceptions induced by applying pressure to the eye ball. They are often described as a glow with arcuate or circular characteristics and are generally perceived in the visual field opposite to the area of pressure. If the object applying the pressure is small, the center of the perceived area appears light with a dark surround and a bright outer portion. However, there is substantial inter-individual variability in how pressure phosphenes are perceived (Chew et al., 2005).

Eyeball deformation leads to an activation of ON-center ganglion cells in the retina, while OFF-center ganglion cells are inhibited. It is thought that the activation of ON-center and inhibition of OFF-center ganglion cells by eyeball deformation are caused by retinal stretching, which may also lead to horizontal cell stretch. Stretching the horizontal cell membrane probably generates an increase in membrane sodium conductivity and a depolarization of the membrane potential. This depolarization of the horizontal cell membrane potential is transmitted either directly or indirectly (via receptor synapses) from the horizontal to the bipolar cells. The bipolar cells, in turn, can activate or inhibit the ganglion cells (Grüsser et al., 1989). Note that in this model, the photoreceptor cells in the retina are not involved - it occurs downstream in the secondary sensory neurons.

References
- Chew et al., Eye (2005) 19: 683–5
- Grüsser et al., Physiol Bohemoslov (1989); 38(4): 289-30


Frequency at which electrodermal response should be measured I'm computer science graduate working on a health monitoring device.

How much is the delay in electrodermal response? i.e., the time it takes before which an electrodermal response can be realized. Basically I want to calculate the rate or frequency at which the measurements should be taken without missing any relevant data.

Can someone please answer or give pointers to some article.

A starting point is the full text chapter "The Electrodermal Response", describes electrodermal response as being based on:

  Interest in the conductance between skin electrodes, usually placed at the palmar surface, arose because of the involvement of the sweat glands in this measurement. Since sweat gland activity, in turn, is controlled by sympathetic nerve activity, this measurement has been considered as an ideal way to monitor the autonomic nervous system

Given that it takes time for processes in the human body to occur, the time delay or latency for the electrodermal response is due to, (from the article):

  If one assumes initial resting conditions, then
  a sweat response consists of sweat rising in the ducts
  , and correspondingly R2 slowly diminishes. The response latency is associated with the time required for this to take place.

Further information that may be of use:

"Electrodermal response propagation time as a potential psychophysiological marker." (Silva et al. 2012). (Unfortunately the article is behind a pay-wall)

An important point from their abstract:

  So far, there is still no clear consensus regarding the relation between the specific responses of the autonomic nervous system activity, and the features typically extracted from the electrodermal activity signals.

However,

  In this paper we present an experimental setup and corresponding data analysis for electrodermal response propagation time measurement.


Why do we use 3 channel R,G,B to represent color? I read that there're some more colors which cannot be represented by R,G,B. What is the experiment that lead people to use 3 variables R,G,B?

Can that experiment be replicated in other modals, such as what is the dimension of auditory perception, or tactile perception?

After researching this a bit more, I believe this is actually a biology question, not a physics one.

The specific term I believe you're searching for is Trichromacy, which Wikipedia defines as:

  Trichromacy or trichromaticism is the condition of possessing three independent channels for conveying color information, derived from the three different cone types.1 Organisms with trichromacy are called trichromats.

Reading the Wikipedia article, it appears that the cone cells  Humans (and other trichromats) come in three different variations; the different variations are sensitive to red, green, and blue light, as depicted in this image (again from Wikipedia)1:

  Normalized responsivity spectra of human cone cells, S, M, and L types

We've evolved these three cone types because red, green and blue are additive primaries, meaning most of the whole range of visible light can be represented by combinations of these colors. Quoting Wikipedia again:

  Even the four-primary technology does not yet reach the range of colors the human eye is theoretically capable of perceiving (as defined by the sample-based estimate called the Pointer Gamut[17]), with 4-primary LED prototypes providing typically about 87% and 5-primary prototypes about 95%. Several firms, including Samsung and Mitsubishi, have demonstrated LED displays with five or six "primaries", or color LED point light sources per pixel.[18] A recent academic literature review claims a gamut of 99% can be achieved with 5-primary LED technology.

I'm not sure what the experiment you're referring to was, but I doubt it would translate nearly as nicely into sound, as RGB is based on the biology of the eye specifically.

1: Attribution: Vanessaezekowitz at en.wikipedia


Psychology test stimuli recommended shapes Is there any list of or a research of recommended 2D (or eventually 3D) shapes that should be used in psychology test stimuli? For example, circle, square, triangle, star, oval, rectangle etc.

For example, I would like to create a cognitive test with multiple elements. I will pick a circle, a square, a triangle and an oval. However, an oval has some properties similar to the circle and that can possibly lead to some distortion in the data. Do you know of any research that has addressed this issue? Or do you know of any list of recommended shapes?

If your goal is to find a set of shapes that are unique and easily distinguishable from each other, you might be interested in stimuli that get used in visual statistical learning experiments (e.g. Fiser & Aslin, 2002; Turk-Browne, Junge, & Scholl, 2005). The same set of shapes tends to get used across multiple studies in this literature. Some examples of these shapes:

There is a repository of some of these shapes on GitHub. You can download the images there.

Note that there hasn't been research on these shapes, just that they are commonly used shapes in the literature when arbitrary 2D shapes are needed. It is likely that some pairs of these shapes are more similar than others, but since there are a couple dozen different shapes, you may be able to control for that by randomly selecting a different subset of the shapes for each subject in the experiment.


What is the term for the rhetorical, "How hard could it be?" I looked through the wikipedia page listing cognitive biases looking for a bias that describes the tendency to assume a poorly understood problem must be simple. Planning fallacy is kind of in the right ballpark; it gets the underestimation part, but I am associating the behaviour with a snap decision more than a plan. Is there another that fits better?

I really thought it would be easy to find this term on wikipedia. I mean, how many psychological terms could there possibly be?

I believe the closest match is the illusion of control:

  ... the tendency for people to overestimate their ability to control
  events; for example, it occurs when someone feels a sense of control
  over outcomes that they demonstrably do not influence. ... people base
  their judgments of control on "skill cues". ... When more of these
  skill cues are present, the illusion is stronger.

This bias only operates when a plausible case can be made for one's skill or intent influencing outcomes - such as a programming task given to a programmer.  In such instances, how well the task or problem is understood, its actual level of difficulty, and the actual level of control over outcomes are overestimated or ignored.

Positive illusions - biases that describe how people overestimate their own abilities, success, and control - are the broader category that contains the illusion of control, and the planning fallacy, among others.  These biases typically go away when estimating the success of others instead of one's self.

There is another bias worth noting here, called the hard-easy effect:

  ... a tendency to overestimate the probability of one's success at a
  task perceived as hard, and to underestimate the likelihood of one's
  success at a task perceived as easy. ... "Hard tasks tend to produce
  overconfidence but worse-than-average perceptions," ...

This bias also ignores how well understood a problem is, but it suggests that a problem perceived as hard (whether or not it actually is) is more likely to result in overestimating success.  This bias is not as robust or widely accepted as the former.


What is the difference between "nudge theory" and "priming"? I'm doing a minor in psychology and during my lesson in both psychological approaches and social psychology, this question popped into my head.
For as far as I know nudge theory is about altering the choice-architecture, but without removing choice. This results in certain (wanted) behaviour. Examples of nudges are: a fly in a urinal; the piano stairs in train stations is way of nudging; stores putting certain brands on eye-level; etc. Where priming is receiving a certain stimulus which creates (temporary) schemes of behaviour.
Could someone help me understand the difference, or how they are connected?
Thanks in advance!

They are not necessarily related concepts, and I think. While nudge (in Thaler's sense) is a mechanism for fostering choice in a planned way, priming refers to a faster processing of new stimuli related to recently activated ones.
It seems like the nudge of might happen through several possible mental processes, including (possibly) priming - although I personally couldn't find any example of how priming could be used to nudge a decision, I'm certain it might. None of the cited examples work through priming, though. For instance, it seems to me that the fly in the urinal example might work through a salience effect (a salient bug in the urinal makes one direct their attention to the salient object).
An example of priming (unrelated to nudge) could be when you see the word "bee", and then see a related stimuli, like the word "honey", and you recognize it faster because there's a previously activated schema. Priming might happen through a lot of means, like words rhyming or starting with the same syllable, semantically related objects, recognition of one object in an abstract pattern, etc. However, in priming there's always at least one prime (a previous stimulus) and one target (a later stimulus) and the prime will make the activation/recognition of the target faster.
Hypothetically, one could use priming to nudge people into "better" decisions if one could offer a prime related to the "best" decision (our target). For instance, consider there is a (widely known) healthy meal and an unhealthy alternative as the options in a restaurant menu. You might put a text saying "Be Healthy" at the cover, which people will see before seeing the alternatives. This might enhance the activation of the healthy alternative, and it might influence the choice (or not). While it's uncertain on whether the healthy food will be chosen, theoretically its activation will be faster due to priming.
SUGGESTED REFERENCES:
Matlin, M. W. Cognition. Hoboken: Wiley, 2012, 8th edition.
Sternberg, R. J. Sternberg, K. Cognitive Psychology. Boston: 2017, 7th edition.


Is there a psychological explanation for the age of 18 being important in many societies? The age of eighteen is an age that in many societies gives rise to various additional rights and responsibilities.

Is there a scientific reason for assigning such right and responsibilities at the age of 18?
What are some of reasons and history for this convention?

A cursory search strongly suggests that the distinction is arbitrary and practical, with little link to developmental science.

I can find no evidence for any particularly compelling biological change centered around the age of 18.  That, along with the fact that the age of eighteen is not a universal age-of-majority, makes me say that there is no scientific basis for the choice.


Studies linking brain chemistry to sexual infidelity This study Oxytocin Modulates Social Distance between Males and
Females examines the effects of Oxytocin (OXT) on men in monogamous relationships. It demonstrates that OXT assists in maintaining fidelity to that relationship. OXT levels are increased by close and sexual interactions with their partner.

  The specificity of the OXT effect in influencing the social distance
  that males keep from unfamiliar females is evidenced by our finding
  that it has no significant effect on the distance kept from unfamiliar
  males. Given the absence of PS differences between single and
  pair-bonded men in the PLC group, it is clear that for these potential
  fidelity-enhancing effects of OXT to be revealed, female partners
  would need to evoke its endogenous release immediately before contexts
  in which the men might encounter other women. While, compared with
  singles, basal concentrations of OXT in blood are increased in couples
  during the early stages of romantic love and stay significantly
  elevated in couples remaining together 6 months later (Schneiderman et
  al., 2012), our results suggest that further augmentation of
  endogenous OXT release is necessary to produce fidelity-enhancing
  effects. Mechanistically, this may be related to additional OXT either
  compensating a relative deficit (optimization hypothesis) or by
  collapsing already optimal levels (decompensation hypothesis). While
  the most obvious physiological stimulus for promoting endogenous OXT
  release in men would be having sex with their mate (Kru¨ger et al.,
  2003), the simple close presence and touch of their partner at any
  given moment in time might also suffice (Holt-Lunstad et al., 2008).
  Thus, OXT effects in promoting monogamy in males may normally depend
  upon the presence of a close positive relationship in the bond with
  their female partners and close physical proximity between the couple.1

There have been studies on the factors involved in  sexual infidelity.

  Virtually all American couples, married or cohabiting, expect sexual
  exclusivity of one another. This article asks why some people are
  sexually exclusive while others have sex with someone besides their
  mate. Previous research has linked personal values, sexual
  opportunities, and quality of the marital relationship to extramartial
  sex. This paper integrates these findings in a multivariate model that
  incorporates factors informing sexual decision making as well as
  demographic “risk factors.” Nationally representative survey data show
  higher likelihood of sexual infidelity among those with stronger
  sexual interests, more permissive sexual values, lower subjective
  satisfaction with their union, weaker network ties to partner, and
  greater sexual opportunities. With these factors controlled, gender
  differences are substantially reduced or eliminated, although racial
  effects persist. 2

Given that there are people who can maintain close relationships, simultaneously, with more than one partner.
Have there been studies examining the  brain biochemistry  that increases  an individual's propensity for sexual infidelity?

1 Oxytocin Modulates Social Distance between Males and Females
Dirk Scheele1, Nadine Striepens1, Onur Güntürkün, Sandra Deutschländer, Wolfgang Maier1,  Keith M. Kendrick, and René Hurlemann
The Journal of Neuroscience, 14 November 2012, 32(46): 16074-16079; doi: 10.1523/JNEUROSCI.2755-12.2012

2 Sexual Infidelity Among Married and Cohabiting Americans
Judith Treas1, Deirdre Giesen2
Article first published online: 2 MAR 2004
DOI: 10.1111/j.1741-3737.2000.00048.

The number one hormonal suspect in infidelity has been testosterone. Partially this has been predicted because testosterone predicts sex drive in both men and women. The problem with testing this one in actual humans though is that most of the things associated with cheating also cause increased testosterone levels (flirting, increased number of sexual partners). Therefore, there's a serious chicken and egg problem in more observational studies.

Roney, J. R., Simmons, Z. L., & Lukaszewski, A. W. (2010). Androgen receptor gene sequence and basal cortisol concentrations predict men’s hormonal responses to potential mates. Proceedings of the Royal Society of London B, 277, 57-63.