WEIRD

In psychology, WEIRD is an acronym for Western, educated, industrialized, rich and democratic &mdash; a capsule description of the undergraduates that the majority of psychological tests are done on. Mostly first-year psychology students. The term is intended to denote awareness that doing all your studies on this tiny group (approximately 10-15% of human population) may not in fact give results indicative of humanity in general, and that such claims may in fact be rubbish.

That this was a potential problem has been vaguely acknowledged (at least in departmental chit-chat, if not in any change in behaviour) ever since psychologists started just doing all their testing on their own undergraduates, but was really bludgeoned home by the 2010 meta-analysis "The weirdest people in the world?" by Joseph Henrich, Steven J. Heine and Ara Norenzayan, in which they trivially showed several claims of universal human behaviour to be nothing of the sort.

Differences
As the majority of WEIRD test subjects are college students and from Western developed nations, the results are skewed. Inclinations that could skew the results are: atypical environment, motor development, diet, cultural differences and the fact that adolescents are more likely to engage in risk-taking behavior.

Japanese and North American students react profoundly differently to failure. Japanese students will study harder to avoid bad grades, while North American students are more likely to give up. In contrast, North American students studied harder when they believed they were going to get good grades, while Japanese students were more likely to study less long.

Results of famous studies such as the Dictator Game can be conflicting when the test subjects are not WEIRD. Foreigners who live in small-scale communities are less likely to transfer a generous amount of money, unlike WEIRD subjects.

Criticism
One anthropologist, Greg Downey, criticized that the acronym "WEIRD" is not sufficient to cover the bias towards Western subjects in research. He went on to elaborate that "democratic", "industrialized", "rich" are terms mainly suited for an understanding of Western inequality, and issues, concluding that the contrasts used in the paper – "small-scale" vs. "Western" – are too simplistic to describe the differences.