Abstract
Compared to notable successes in the genetics of basic sensory transduction, progress on the genetics of higher level perception and cognition has been limited. We propose that investigating specific cognitive abilities with well-defined neural substrates, such as face recognition, may yield additional insights. We used a classic twin design to determine the relative contributions of genes and environment to face recognition ability. Our measure of face recognition ability was the widely used Cambridge Face Memory Test (CFMT), a reliable, normed, well-validated test requiring study and then recognition of faces in novel views and novel lighting. We found that the correlation of scores between monozygotic twins (0.70) was both statistically indistinguishable from our measure's test-retest reliability (0.70) and more than double the dizygotic twin correlation (0.30), evidence that genetic influence accounts for all of CFMT's familial resemblance and for a very large proportion of its total stable variation. We also used an individual differences based study to dissociate face recognition ability from other abilities. A low correlation between CFMT and verbal recognition (0.17) demonstrated that the heritability we observed for CFMT was not the result of motivation, attention, computer-literacy, or general memory. A modest correlation between CFMT and abstract art recognition (0.26) indicated that general visual processes make only limited contributions to CFMT performance. Our results therefore identify a rare phenomenon in behavioral genetics: a highly specific cognitive ability that is highly heritable. These results establish a clear genetic basis for one of the most intensively studied and socially advantageous of cognitive traits, opening a new domain to genetic investigation.
Funding for this project was provided by the Economic and Social Research Council to BD, an NIH fellowship to JW, an NSF grant to J. Richard Hackman and Stephen M. Kosslyn, and a DCI Postdoctoral Fellowship to CFC. This research was facilitated through the Australian Twin Registry which is supported by an Enabling Grant from the National Health & Medical Research Council administered by The University of Melbourne.