Differential onset of infantile deprivation produces distinctive long‐term effects in adult ex‐laboratory chimpanzees (Pan troglodytes)

Abstract

Maternal or social deprivation during early infancy inevitably produces social deficiencies in juvenile chimpanzees. Hypothesizing such deficiencies to persist into adulthood (a), and, as in humans, a sensitive period in early infancy for attachment formation (b), we predicted and found behavioral differences in resocialized adult ex-laboratory chimpanzees after about 20 years of solitary confinement depending on their age at onset of deprivation: early deprived (ED; mean: 1.2 years) chimpanzees engaged significantly less in social interactions, spent less time associated, and showed more nonsocial idiosyncrasies than did late deprived (LD; mean: 3.6 years) chimpanzees. In addition to these individual attributes relational qualities, specifically the combination of ED and LD chimpanzees within social groups, have an impact on social recovery. LDs can best exploit their social potential in the company of other LDs and EDs tend to stagnate in their recovery when socialized with other EDs.

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

“…Chimpanzees that were younger when rehabilitation began reached higher levels of behavioral and social competence and spent more time in positive behaviors such as social play and affiliative behaviors and less time being inactive. These results reflect earlier findings (Kalcher et al 2008) and suggest that the development and recovery of social and behavioral deficiencies are clearly related to the age at the onset of rehabilitation.…”

“…The goal is to promote the development of species-typical behaviors, by enhancing their welfare and social skills. Several studies have determined that chimpanzees with a previous history of maltreatment or unfavorable rearing conditions can be rehabilitated and resocialized over time (Kalcher-Sommersguter et al 2013;Kalcher et al 2008). However, most of this evidence comes from former laboratory chimpanzees (Reimers et al 2007), where chimpanzees that were caged singly at an early age (mean 1.2 yr) present higher levels of social competence than those caged singly at a later age (mean 3.6 yr) (Kalcher-Sommersguter et al 2011).…”

“…Prolonged captivity, sensory deprivation, and use in laboratories have been shown to contribute to behavioral pathologies in nonhuman primates (Anderson 2010;Bellanca and Crockett 2002;Bradshaw et al 2008;Kalcher et al 2008;Llorente and Campi 2014;Novak 2003;Rodríguez-Rodríguez et al 2010), including abnormal behaviors such as floating limb (Bentson et al 2010), self-biting (Reinhardt and Rossell 2001), self-injury (Wielebnowski et al 2002), self-clasping (Buttelmann et al 2008), pacing (Rybiski Tarou et al 2005), rocking (Lopresti-Goodman et al 2012), object attachment (Janson 2012), coprophagy (Nash et al 1999), and regurgitation-reingestion (Baker and Easley 1996). Poor conditions early in life may also affect personality (Martin 2005) and the development of mental disorders later in life (Brüne et al 2004;Ferdowsian et al 2011Ferdowsian et al , 2012Troisi, 2005).…”

A Behavioural Case Study of Early Social Isolation of a Subadult White-Handed Gibbon (Hylobates lar)

“…The male gibbon may have recognised the female conspecific as a more desirable social partner than humans. The gibbon never showed aversive reactions [Harlow et al, 1965;Cheyne, 2006;Clarke et al, 2006;Kalcher et al, 2008] and on the second day exhibited social patterns, and the 2 gibbons started covocalising from the fourth day. When in physical contact, normal levels of malefemale social interactions were established on the fifth day.…”

Emotion as an Intervening Variable in Understanding the Cognitive and Social Complexity and Well-Being of Chimpanzees

“…Many studies have shown that early social deprivation results in decreased species-typical behaviors, impaired cognitive abilities, and increased abnormal behaviors among chimpanzees (Davenport, Rogers, & Rumbaugh, 1973;Turner, Davenport, & Rogers, 1969). Such effects may persist throughout the lives of affected individuals (Kalcher, Franz, Crailsheim, & Preuschoft, 2008;Martin, 2002). In the wild, chimpanzee infants who lost their mother demonstrated clinical symptoms of depression such as reduced physical and social activity, reduced playfulness, and increased abnormal behavior (Goodall, 1986).…”