Examples Improve Facial Identity Comparison

Everyday security tasks, such as passport control, require comparison of peoples’ faces with portrait photographs to assert their identities. These facial comparisons can be very difficult, even for experienced personnel who conduct these identifications regularly. This study investigated whether the provision of defined examples, labelled clearly as identity matches or mismatches, improves the accuracy of facial image comparison. Examples increased accuracy compared to a no-examples control group, especially in individuals who were initially least good at performing facial comparisons. This benefit persisted after examples were withdrawn. We suggest that people have inherently poor criteria for making facial comparisons due to the many ways in which faces can vary. Provision of examples might improve accuracy by supplying criteria for facial comparison that participants would otherwise have to deduce by their own judgement.