Monkeys and mug shots: cues used by rhesus monkeys (Macaca mulatta) to recognize a human face.

We investigated the cues rhesus monkeys (Macaca mulatta) use to recognize a familiar human face. To manipulate facial cues, schematic faces were constructed with Identi-Kit materials derived from mug shots. The monkeys (N = 4) spontaneously classed Identi-Kit as faces on initial presentations. The monkeys then learned to distinguish one Identi-Kit face, the standard, from others. Panel presses indicated recognition of the standard face. Eye movement recordings revealed that the monkeys predominantly fixated on the eyes of the standard face. When the standard face was transformed by removing, altering, or reorienting its features, only alterations of eyes or brows lowered recognition; removal of eyes, brows, nose, or lips did not. Responses to rotated, inverted, and scrambled versions of the standard face varied but generally disrupted recognition. We concluded that features and configuration were used to recognize the human face.

The relationship of social power to visual displays of dominance between men and women.

Two studies, with undergraduate subjects, investigated how sex and situation-specific power factors relate to visual behavior in mixed-sex interactions. The power variable in Study 1 was expert power, based on differential knowledge. Mixed-sex dyads were formed such that members had complementary areas of expertise. In Study 2, reward power was manipulated. Consistent with expectation states theory, both men and women high in expertise or reward power displayed high visual dominance, defined as the ratio of looking while speaking to looking while listening. Specifically, men and women high in expertise or reward power exhibited equivalent levels of looking while speaking and looking while listening. High visual dominance ratios have been associated with high social power in previous research. Both men and women low in expertise or reward power looked more while listening than while speaking, producing a relatively low visual dominance ratio. In conditions in which men and women did not possess differential expertise or reward power, visual behavior was related to sex. Men displayed visual behavior similar to their patterns in the high expertise and high reward power conditions, whereas women exhibited visual behavior similar to their patterns in the low expertise and low reward power conditions. The results demonstrate how social expectations are reflected in nonverbal power displays.