The function and specificity of sensitivity to cues to facial identity: an individual-differences approach.

The expertise of adults in recognising the identity of individual faces has been attributed to their exquisite sensitivity to differences among faces in the spacing of features (second-order relations). However, the reliability of individual differences and the extent to which this sensitivity predicts individuals' ability to recognise faces has not been tested directly. We administered two sets of tasks to adult females (n = 31); the tests were separated by 2 to 11 days. Individual differences in sensitivity to the spacing of facial features were reliable across days and correlated with individual differences in sensitivity to the spacing of features (doors and windows) in houses, but did not predict accuracy when participants matched facial identity across changes in point of view. Individual differences in sensitivity to featural cues to facial identity were not reliable, likely because of ceiling effects. The function and specificity of sensitivity to the spacing of features is discussed.