Facial stereotypes and perceived mental illness

It is well established that we carry stereotypes that impact on human perception and behaviour (e.g. G.W. Allport, "The nature of prejudice". Reading, MA: Addison-Wesley, 1954). Here, we investigate the possibility that we hold a stereotype for a face indicating that its owner may have a mental illness. A three-stage face-perception experiment suggested the presence of such a stereotype. Participants first rated 200 synthetic male faces from the EvoFIT facial-composite system for perceived mental illness (PMI). These faces were used to create a computer-based rating scale that was used by a second sample of participants to make a set of faces appear mentally ill. There was evidence to suggest that the faces that participants identified using the PMI scale differed along this dimension (although not entirely as expected). In the final stage of the study, another set of synthetic faces were created by artificially increasing and decreasing levels along the scale. Participants were asked to rate these items for PMI and for six criminal types. It was found that participants assigned higher PMI ratings (cf. veridical) for items with inflated PMI (although there was no reliable difference in ratings between veridical faces and faces with decreased PMI). Implications of the findings are discussed.