#Chimpanzee eyes full size#

The chimpanzee eye corresponds closely to the human eye, the chief differences being related to the structures of the anterior chamber angle. Eye-tracking studies have shown that chimps and humans scan faces in similar ways, paying special attention first to the eyes, and then to the mouth. No significant differences related to age could be identified.

“It would be especially useful to know when in evolution human's highly visible eyes originated, as this would suggest a possible date for the origins of uniquely human forms of cooperation and communication,” Tomasello and colleagues write. Here, we present the first examination of eye tracking in chimpanzees. Thirteen eyes of normal chimpanzees from 1-34 to 15 years of age were serially sectioned for histological study. If correct, the cooperative eye hypothesis could provide a valuable clue about when we became the social beings that we are. Charla Nash, the 55-year old woman who was mauled by the 200-pound, 14-year old chimpanzee, lost both her eyes, her nose and part of her jaw in the Monday attack, MSNBC television reported today. Tomasello and his team note in their paper that 'these hypotheses are not mutually exclusive, and highly visible eyes may serve all of these functions.' Description: Chimpanzee (Pan troglodytes) in northern Zambia. The study, conducted by Haley and Daniel Fessler, also at UCLA, found that people were more generous and donated more money if they felt they were being watched - even if the watchful eyes were just drawings resembling eyes on a computer screen. Or, as one other recent study suggested, visible eyes might be important for promoting cooperative and altruistic behavior in individuals that benefit the group.

#Chimpanzee eyes full size#

The setting was covered by a black cloth during the experiment Full size image Stimuli The targeted body part was either one arm or one leg. For example, white sclera might signal good health and therefore help signal to others our potential as a mate. When chimpanzees drank juice from the tube, their eyes stayed at approximately the same horizontal level as the center of the screen. Other ideas have also been proposed to explain why humans have such visible eyes.