Face Recognition from Birth
The face recognition system is active before birth. Foetuses show orientation responses to face-like stimuli projected onto the uterine wall at 34 weeks of gestation. Newborns, within hours of birth, preferentially track face-like stimuli over scrambled face stimuli, they already have an innate preference for face-like configurations, despite having no visual experience with faces.
This innate preference reflects genetically pre-specified tuning of subcortical visual pathways to the spatial frequency and configuration characteristic of faces. It is not learned; it is built in as a starting point for the learning that follows.
The Learning Curve
From birth, experience with faces begins rapidly tuning the face recognition system. Infants at 3 months can distinguish between individual human faces but also between individual monkey faces. By 6 months, the other-species advantage disappears, they have become specialised for the human faces that dominate their visual experience. This is a clear demonstration of perceptual learning: the own-race/own-species effect begins in infancy.
By approximately 6 years of age, children can match unfamiliar faces comparably to adults in many conditions, though the system continues maturing through adolescence. The full face recognition capability, including reliable unfamiliar face matching, reaches its peak in young adulthood.