The Emotional Impact of Faces (But Not Names): Face Specific Changes in Skin Conductance Responses to Familiar and Unfamiliar People
Skin Conductance Responses to familiar and unfamiliar names and faces were recorded from independent groups of subjects, using two different presentation designs: the first employing fewer familiar than unfamiliar items and the second employing equal numbers of familiar and unfamiliar items. The fact that, under normal circumstances, familiar faces yield greater autonomic activity than do unfamiliar faces raises the question as to why this should occur. Tranel et al. argued that known faces are more “significant” stimuli than unknown faces and that this attribute induces greater autonomic activity. Social animals need to distinguish in-group from out-group members and to discriminate high- from low-status members, as well as recognize those who are kin from those unrelated. The face not only provides the richest source of the identity information, of course, but also conveys details of health, age, attractiveness, intentions, mood, etc.