Infants' responses to male and female faces and their preferences for happy versus fearful faces were studied to extend findings indicating that infants at 7 months can generalize discrimination between expressions of happiness and surprise across four different female models' faces. In the first experiment, a paired-comparison procedure was used in which 32 7-month-old infants were presented with three 30-second familiarization trials followed by two 10-second test trials. Half the infants were familiarized to happy faces and tested on fearful expressions; half were familiarized to fearful faces and tested on happy expressions. Observers recorded infants' looking times. Data from test trials were pooled, yielding one score for novelty and one for familiarity. Looking times were incorporated into an analysis of variance comparing happy-to-fear versus fear-to-happy groups and novel versus unfamiliar stimulus. A second experiment with 7-month-old infants examined whether a relative looking preference would emerge if infants were presented with a happy face paired with a fearful face. Overall, results suggested that (1) infants perceive facial expressions of happiness and fear in a categorical fashion, although their doing so depends in part on the order of stimulus presentation; and (2) a relative looking preference for fearful faces exists when such faces are paired with happy faces. (RH)