Three experiments with 91 college students examined the effects of social categorization on memory for behaviors associated with in-group and out-group members. In Exp I, it was predicted and found that social categorization generates the implicit expectancy that the in-group engages in more favorable and/or less unfavorable behaviors than does the out-group. To test the hypothesis that such expectancies bias memory for behaviors associated with in-groups and out-groups, Ss in Exp II were given favorable and unfavorable information about in-group and out-group members and were later tested for recognition memory. Ss showed significantly better memory for negative out-group than for negative in-group behaviors. Exp III assessed the locus of the memory effect and found that the effect could not be attributed to a simple response bias. Implications for intergroup perception are discussed. (17 ref) (PsycINFO Database Record (c) 2016 APA, all rights reserved)