This bias manifests itself in, for example, Wason selection task (1966). This task tests logical reasoning; it consists on presenting subjects with 4 cards, each of which has a color on one side and a specific form (a circle or a square) on the other. Subjects are asked to indicate which card or cards they must turn over in order to determine if a certain rule is true. After several studies using the original abstract task were carried out, new variants of it were designed, in which variables related to the social context are crucial (Griggs & Cox, 1982).
