Development of social cognition in infant chimpanzees (Pan troglodytes): Face recognition, smiling, gaze, and the lack of triadic interactions¹

Abstract

In this paper, we summarize a series of studies on the developmental changes in social cognition in mother-raised infant chimpanzees from birth to around 2 years old. The infants preferentially tracked a photograph of their mother's face at 1 month but showed indifferent preferences to faces at 2 months old. This change in facial recognition was correlated with a decrease in neonatal spontaneous smiling, increase in social smiling and a decline in neonatal imitation of facial expressions. Also at around 2 months, the infants began to show preferences for directed-gaze faces over averted gazes, and the amount of

Rhesus monkeys show human-like changes in gaze following across the lifespan

“…Similarly, apes may not show basic co-orienting responses when others move the direction of their gaze, nor more complex forms of reasoning about others' line of sight (e.g. accounting for barriers and distractors) until they are several years old [24,[32][33][34][35][36]. Overall, this evidence supports the proposal that gaze following in non-human primates requires more extensive experience with relevant social interactions than is necessary for humans (e.g.…”

“…We adopted this approach because rhesus monkeys spontaneously follow the gaze of both conspecifics [42,43] and humans [35]. The actor rotated her entire head upward (with her eyes open), because previous work indicated that macaques show robust gaze-following responses to such cues [35,36], and primates generally are less sensitive to eye cues alone [21,54]. Although it remains possible that monkeys of different ages had different levels of experience with humans and thus responded differentially to the human actor, we note that as a whole this population is highly habituated to human observers from infancy.…”

Comparative Developmental Psychology: How is Human Cognitive Development Unique?

“…Finally, infant chimpanzees and an infant gibbon recognize and prefer the face of their mother or human caregiver over less familiar faces at 1 month of age (Myowa-Yamakoshi and Tomonaga, 2001a;Tomonaga et al, 2004), much like human infants (Pascalis, Deschonen, Morton, Deruelle, and Fabregrenet, 1995). Taken together, these results show that humans and apes exhibit similar developmental trajectories in early infancy, suggesting that human patterns have deep biological roots.…”

Cats and Illusory Motion

“…Encouraged by these results we performed a preferential looking experiment, an experimental paradigm first used to investigate infant's vision (Fantz, 1963) but recently also used in animal experiments (Shirai et al, 2010;Tomonaga et al, 2004;Shirai & Imura, 2014). This experiment was conducted in a "cat-café" in Fukuoka-city.…”