On leaping to conclusions when feeling tired: Mental fatigue effects on impressional primacy

An experiment examined the impact of mental fatigue on impression formation. Subjects experiencing fatigue as a result of participation in a lengthy final examination at a university manifested greater magnitude of primacy effects in impressions than did nonfatigued subjects. Those differences disappeared when subjects were held accountable for their impressions. The findings are discussed in reference to the possibility that fatigue renders information processing subjectively costly inducing the need for cognitive closure (Kruglanski, in press) promoting a ''freezing'' on impressions implied by early information about a social target. Similarly, need for closure is assumed to be lowered by accountability concerns. This analysis is discussed in light of the alternative possibility that the effects of fatigue on impressions stem from a depletion of cognitive capacity. (C) 1996 Academic Press, Inc.