Development of face recognition in an infant gibbon (Hylobates agilis)
The development of the ability to recognize faces was studied in a nursery-reared male infant gibbon (Hylobates agilis). We used traditional and modified head-turning procedures that measured the infant’s eye- and head- tracking of moving stimuli. In Experiment 1, the infant was presented with face-like and nonface-like drawings. He showed a preference for face-like stimuli. Experiment 2a tested the infant’s recognition of photographs of familiar and unfamiliar faces; by 4 weeks of age, the infant preferred looking at a familiar human face to unfamiliar faces. Experiment 2b investigated the infant’s sensitivity in acquiring a preference for faces. The infant was more sensitive to the characteristics of a familiar human face than to those of unfamiliar faces. These findings suggest that there may be similarities between the early face recognition ability of humans and gibbons.