Jackson Arn in The Hedgehog Review:
Psychology is always in the midst of trading itself out. Seven years from now, a recent study estimated, about half of what psychologists believe will have been replaced with something new.1 Pop psychology, on the other hand, is ageless. Its big ideas (six degrees of separation, mothers lifting pickups off their babies, you only use 10 percent of your brainpower) have survived every regime change. They cannot be disproven because they were never completely true in the first place.
In the early 1960s, three events occurred that had a sizable influence on psychology but a massive influence on pop psychology. Taken together, they seemed to suggest a frightening truth about human nature—so frightening that people were afraid to ignore it, even as more and more of the evidence was contradicted. The first event was the trial, beginning in May 1961, of the Nazi official Adolf Eichmann. The second was the “shock experiment” organized by the psychologist Stanley Milgram in July of the same year. The third was the murder of Kitty Genovese in March 1964.
More here.