An experimental procedure in which mere social categorization elicits intergroup discrimination. It was introduced in 1970 and 1971 in articles in Scientific American magazine and the European Journal of Social Psychology respectively by the British-based Polish psychologist Hanri Tajfel (1919–82) and several colleagues, who performed the following experiment with a group of 64 schoolboys who knew one another very well. The boys were divided into two groups on arbitrary and insignificant criteria and were then presented with a series of two-row matrices, on each of which they were asked to choose a column specifying amounts of money to be assigned to two members of their own group (ingroup choices), two members of the other group (outgroup choices), or one member of their own group and one member of the other group (intergroup choices). The boys did not know the identity of the individuals who were affected by their choices but only which groups they belonged to, and their own interests were not affected by their choices, because no one could know their choices. Nevertheless, when they made intergroup choices, a large majority of the boys gave slightly more money to members of their own group than to members of the other group, even when they could have chosen columns in which members of their own group would have got more in absolute terms but the other group would have done even better. In contrast, when they made ingroup choices or outgroup choices, they tended to select columns that distributed the money with maximum fairness. This effect has been replicated with children and adults of both sexes in many different countries. Also called the minimal group paradigm, and often confused with the minimal social situation. See also social identity theory.