The goal of this dissertation was to better characterize the nature of infants’ visual preference for own-race faces, and to test two theories regarding its origin. Chapters I and II assessed whether the race bias in infancy could be attributed to an enhanced ability to discriminate familiar faces. Based on this account, infants' race preference should be more pronounced for female pairs of faces, and should only arise whenever different individuals are presented across trials. In Chapter I, White 3-month-old infants saw multiple male and female pairs differing in race. Looking times revealed a significant own-race preference only when male faces were presented. In Chapter II, participants viewed different photographs of the same two Black and White faces across 8 trials. Findings still revealed a robust own-race visual bias uniquely in male pairs. Collectively, these findings provide evidence against the notion that differences in face discriminability are responsible for babies’ racial preference. Moving to the question of origin, Chapter III tested the hypothesis that the male-specific own-race preference is rooted in an evolutionary threat response. Participants were presented with male and female pairs of own-and other-race faces displaying averted eye gaze, a cue meant to reduce threat. Findings were inconclusive as a looking time bias specifically toward White males yet again emerged. Finally, Chapter IV examined the idea that infants’ early visual preferences are shaped by experience. Three-month-olds were shown a video of an own- and other-race male addressing them in an infant-directed manner. Immediately following the video presentation participants’ visual preference for the two men depicted in the film was measured. Though the own-race preference persisted, looking times toward the Black male were significantly higher in comparison to a group of infants who received no exposure. These results are novel in revealing an own-race bias that is dependent on target gender, suggesting that gender is a stronger cue than race in guiding infants’ responses. Furthermore, though exposure did not attenuate overall preference, the findings point to the potential benefit of using such manipulations for changing bias in future research. / Psychology

During the early stages of infant development the capacity for perceptual (i.e., visual) discrimination is shaped by infants' perceptual experience. Perceptual narrowing is one process hypothesized to account for developmental change. Perceptual narrowing research often demonstrates that infants before 6 months of age are able to discriminate a wide variety of events whereas infants beyond 6 months of age seemingly "lose" some perceptual abilities. Two investigations are proposed to examine the claim that younger, but not older infants can discriminate faces across species. The purpose of Experiment 1 was to determine whether an increase in familiarization and trial times would result in cross-species facial (i.e. faces of macaques) discrimination in 12-month-olds. The hypothesis was supported, adding evidence that perceptual discrimination becomes more constricted, or less efficient with age, but does not decline. Experiment 2 examined whether reducing both the time of familiarization and comparison time by 50% would allow infants sufficient time to discriminate. Results were consistent with the hypothesis and previous studies were corroborated. These findings highlight the important role of perceptual experience in young infants' perceptual discrimination abilities and provide a greater degree of clarity regarding present use of the concept perceptual narrowing.