The field of psychology is going through a period of introspective turmoil. One the one hand, it has never been more popular. Its results lead to attention-grabbing headlines, and fill books that sit happily on bestseller lists. Conversely, some of its own practitioners are starting to ask themselves a difficult question: What proportion of the field’s findings are genuine and reliable insights into the human mind, and what proportion are red herrings produced by questionable research practices and, in rare cases, outright fraud?

This line of questioning comes from: cases of classic results that cannot be easily reproduced; studies that have documented widespread dodgy practices that lead to false results; the publication of papers that claim