Individual differences in children's facial expression recognition ability: The role of nature and nurture.

We examined genetic and environmental influences on recognition of facial expressions in 250 pairs of 10-year-old monozygotic (83 pairs) and dizygotic (167 pairs) twins. Angry, fearful, sad, disgusted, and happy faces varying in intensity (15%-100%), head orientation, and eye gaze were presented in random order across 160 trials. Total correct recognition responses to each facial expression comprised the dependent variables. Twin data examined genetic and environmental contributions to variables and their correlations. Results support a common psychometric factor influenced primarily by additive genetic influences across expressions with discrimination of specific expressions due largely to non-shared environmental influences.