The piece has its origins in an incident that regular readers will already know. In January, Stephane Doyen and colleagues had unsuccessfully tried to repeat a classic experiment where people walk more slowly down a corridor after being unconsciously primed with age-related words. I wrote about their research. Two months later, the man behind the original study – John Bargh of Yale University – wrote a scathing attack on Doyen’s team, me, and the journal that published the study. I responded.

The ensuing discussion opened my eyes to an undercurrent of unrest. Many psychologists came out of the woodwork to mention experiments that were hard to replicate, common practices that they deemed to be dodgy, and a growing