Although we initially tend to pay attention to obvious features such as hair, it has been long established that familiar faces are recognized better from their inner (eyes, nose, mouth) rather than their outer (hair, hairline, jaw, ears) parts1. Studies have shown that this advantage of inner features does not occur in children until they’re around 10—11 years old. Children younger than this tend to use outer features to recognize people they know2.
Studies investigating the inner-face advantage have used photographs in which parts of faces have been cropped. This may be confusing to young children. It was thought that inner-face processing would be facilitated if blurring was used instead. Accordingly, in this study photographs in which either the inner face or the outer features are blurred were used.
Although it was thought that this would encourage inner-face processing, children seemed to find it harder. Extending the experiment to adolescents, it was found that the inner-face advantage typical of adults, did not appear until 14—15 years of age. A further experiment with learning-disabled adolescents, with a mental age of 5—8 years, found no shift to inner-face processing. This suggests that the shift to inner-face processing is a developmental change, rather than simply reflecting a need to gain sufficient experience in face-processing.
References
1. Ellis, H.D., Shepherd, J.W. & Davies, G.M. 1979. Identification of familiar and unfamiliar faces from internal and external features: Some implications for theories of face recognition. Perception, 8, 431-439.
2. Campbell, R. & Tuck, M. 1995. Children’s recognition of inner and outer face-features of famous faces. Perception, 24, 451-456.
Campbell, R., Walker, J. & Baron-Cohen, S. 1995. The use of internal and external face features in the development of familiar face identification. Journal of Experimental Child Psychology, 59, 196-210.