Did Fischer really have a 180 IQ? I have read many times that Bobby Fischer had an IQ of 180. Did he really have that high of an IQ? Does anyone have proof that he was ever even tested (like a citation from an early book about him)?
Sure, Fischer was an intelligent guy, but I tend to think that someone once made up that number, and it just stuck. Lately, I have seen the same, suspiciously rounded, number given to Kasparov and Carlsen.
A 180 IQ is so rare that most people have probably never met someone, who was officially tested, with such a high IQ. Thus, maybe they just assumed it must be super high, and threw out a number. 180 is in the 99.9999712895 percentile. 140 is already considered a genius and is in the 99.3790320141 percentile.
How can one even tell by just listening to his interviews if he was that intelligent? Is there any legitimate way to prove that claim or disprove it?
From Quora: What was Bobby Fischer's IQ? (2018):


  Short answer: In 1958, when Fischer sat a Stanford-Binet test at the age of 15, his score was 180-187. But in today’s terms, Bobby Fischer’s IQ should be 148–155 on the Fifth edition of the Stanford-Binet test, and 150-160 on the WISC-V/WAIS-IV tests administered by Mensa.


The only reference provided for the 180-187 score is a link to the webpage The Mind of Bobby Fischer by Frank Brady where it states that 


  In previous writings I have cited Fischer's I.Q. as in the range of 180, a very high genius. My source of information is impeccable: a highly regarded political scientist who coincidentally happened to be working in the grade adviser's office at Erasmus Hall - Bobby Fischer's high school in Brooklyn - at the time Fischer was a student there. He had the opportunity to study Fischer's personal records and there is no reason to believe his figure is inaccurate. Some critics have claimed that other teachers at Erasmus Hall at that time remember the figure to be much lower; but who the teachers are and what figures they remember have never been made clear.


The given rationales for the deflation of the score per today's standard are the Flynn effect based on a large meta-analysis that every year general intelligence increases by 1/3 IQ points, and the revised editions of the S-B test.