According to Joseph Henrich and his colleagues at the University of British Columbia, most undergraduates are WEIRD. Those who teach them might well agree. But Dr Henrich did not intend the term as an insult when he popularised it in a paper published in Behavioral and Brain Sciences in 2010. Instead, he was proposing an acronym: Western, Educated, Industrialised, Rich and Democratic.

One reason these things matter is that undergraduates are also psychology’s laboratory rats. Incentivised by rewards, in the form of money or course credits, they will do the human equivalents of running mazes and pressing the levers in Skinner boxes until the cows come home.

Which is both a blessing and a problem. It is a blessing because it provides psychologists with an endless supply of willing subjects. And it is a problem because those subjects are WEIRD, and thus not representative of humanity as a whole. Indeed, as Dr Henrich found from his analysis of leading psychology journals, a random American undergraduate is about 4,000 times more likely than an average human being to be the subject of such a study. Drawing general conclusions about the behaviour of Homo sapiens from the results of these studies is risky.

This state […]