Implicit partisanship: taking sides for no reason.

After spending 45 s studying the names of 4 members of a hypothetical group, subjects showed both implicit liking and implicit identification with the group. These effects of studying names were much larger than the mere exposure (R. B. Zajonc, 1968) effects of either 6 (Experiment 2) or 10 (Experiment 3) extra exposures to each name. This implicit partisanship effect differs from the minimal group effect (H. Tajfel, 1970) because its procedure involves no membership in the target group. It also differs from the mere exposure effect because the target stimuli are presented once as members of a group rather than multiple times as unrelated individuals. A plausible (but not established) interpretation is that the attitude and identification effects are consequences of mere categorization.