Extraversion-introversion and the effects of favorability and set size on impression formation

In an impression formation task extraverts (n = 20) and introverts (n = 20) were asked to rate the likability of target persons described by varying numbers of favorable or unfavorable traits. The extraverts rated target persons described by favorable traits as more likable (p <.05) and target persons described by unfavorable traits as less likable (p <.05) than did the introverts. These findings support the hypothesis that the differences in social responsiveness between the extravert and the introvert are a product of two processes. First, the extravert, because of his stronger need for stimulation, is more likely than the introvert to interact with other persons. Second, as a result of this interaction the extravert learns to be more responsive to both the positive and negative reinforcement potential of other persons.