Early social deprivation negatively affects social skill acquisition in chimpanzees (Pan troglodytes)

Abstract

In a highly social species like chimpanzees, the process by which individuals become attuned to their social environment may be of vital importance to their chances of survival. Typically, this socialization process, defined by all acquisition experiences and fine-tuning efforts of social interaction patterns during ontogeny, occurs in large part through parental investment. In this study, we investigated whether maternal presence enhances the socialization process in chimpanzees by comparing the social interactions of orphaned and mother-reared individuals at the Chimfunshi Wildlife Orphanage Trust in Zambia. As response variables, we selected social interactions during which an elaborate level of fine-tuning is assumed to be necessary for sustaining the interaction and preventing escalation: social play. Comparing orphaned (n = 8) to sex- and age-matched mother-reared juvenile chimpanzees (n = 9), we hypothesized that the orphaned juveniles would play less frequently than the mother-reared and would be less equipped for fine-tuning social play (which we assayed by rates of aggression) because of the lack of a safe and facilitating social environment provided by the mother. First, contrary to our hypothesis, results showed that the orphaned juveniles engaged in social play more frequently than the mother-reared juveniles, although for significantly shorter amounts of time. Second, in support of our hypothesis, results showed that social play of the orphaned juveniles more often resulted in aggression than social play of the mother-reared juveniles. In conjunction, these results may indicate that, just like in humans, chimpanzee mothers provide their offspring with adequate social skills that might be of pivotal importance for future challenges like successful group-living and securing competitive fitness advantages.

Bushmeat trade consequences predict higher anxiety, restraint, and dominance in chimpanzees

“…Infant wild chimpanzees spend their first two or three years very close and physically clinging to its mother (Bard, ). A lack of early social relationships and other traumatic early life events can have deleterious effects later in life in humans (Bos et al, ), chimpanzees (van Leeuwen, Mulenga, & Chidester, ), and other nonhuman primates (Kerr, Chamove, & Harlow, ). Either the quantity or quality of the parental care has lasting and profound cognitive and emotional consequences (Gilmer & McKinney, ).…”

Effects of Paternal Predation Risk and Rearing Environment on Maternal Investment and Development of Defensive Responses in the Offspring

“…SNH rearing decreased grooming in male and female offspring. Maternal deprivation studies have identified deficits in sociality in offspring (Schneider and Koch, 2005; van Leeuwen et al, 2014). However, this difference in grooming could also be a manifestation of sex differences in play behavior, as male offspring engage in more attack grooming while females engage in more social grooming (Parent and Meaney, 2008).…”

Rehabilitation and Socialization of Chimpanzees (Pan troglodytes) Used for Entertainment and as Pets: An 8-Year Study at Fundació Mona

“…A secure emotional attachment to the mother is also a crucial component of normal social development (Tomonaga 2006;van Ijzendoorn et al 2009). The absence of the mothers, peers, or conspecifics, in wild or captive settings during sensitive periods of infancy, can have deleterious effects later in life (van Leeuwen et al 2014).…”