What is the history of the character “耻”? The meaning of the word is “shame”. I often encounter the version which is written with a 止, but sometimes I confuse it with 恥. It seems that the meanings of 耻 and 恥 are both the same, just that one is a simplified character and the other, traditional. 

How did two versions of the same word come about, and why would one be considered “simplified”, given that the number of strokes are similar?
戰國・楚簡緇衣.28郭店楚簡篆心部說文解字東漢隸樊敏碑　今楷　

「恥」 (Baxter-Sagart OC: /*n̥rəʔ/, humiliation/shame) is comprised of semantic 「心」 (heart, mind) and phonetic 「耳」 (/*C.nəʔ/).

During times when clerical script was in active use, the 「心」 portion of the character was sometimes corrupted into an additional sound hint 「止」 (/*təʔ/). This produces the variant 「耻」, which is the target of PRC's standardisation scheme.

東漢隸樊敏碑　東漢隸孔宙碑　東漢隸池陽令　今楷