Why are attractive faces preferred?: an electrophysiological test of averageness theory

Numerous studies provide evidence that 6-month-old infants have visual preferences for faces judged by adults to be attractive well before these preferences might be acquired through socialization mechanisms (e.g. Langlois et al., 1987; Slater et al., 1998). Why do infants and adults prefer attractive faces? Averageness theory asserts that attractive faces are more 'average' in configuration and closely resemble the mean of a population of faces and are thus more familiar, typical, and 'face-like', than faces that deviate (e.g., unattractive faces) from the average configuration (Langlois & Roggman, 1990). When faces are averaged together, the resulting average configuration is judged to be highly attractive (e.g., Langlois & Roggman, 1990). Fluency theories suggest that fluent processing of prototypical exemplars (e.g., attractive faces, averaged faces) evokes positive affect (e.g., Winkielman et al., 2003). Therefore, because adults and even 6-month-olds can form prototypes of the faces they experience (e.g., Rubenstein et al., 1999), they may prefer attractive faces because they are more prototypical, and thus, more quickly and easily processed than less attractive faces. I tested fifty 6-month-old infants and forty-four adults and used event-related potentials (ERP) to record their brain activity in response to averaged, attractive, and unattractive faces. Consistent with averageness and fluency theories, results revealed lower amplitudes and shorter latencies to less attractive faces in infant and adult ERP components associated with face processing. Infant ERPs also showed a pattern of activity that suggested that attractive faces are processed as familiar compared to less attractive faces. The results suggest that more attractive faces are more fluently processed than less attractive faces and thus, both infants and adults may prefer attractive faces because they are more quickly and easily processed.