Chimpanzee and Human Risk Preferences Show Key Similarities

Abstract

Risk preference impacts how people make key life decisions related to health, wealth, and well-being. Systematic variations in risk-taking behavior can be the result of differences in fitness expectations, as predicted by life-history theory. Yet the evolutionary roots of human risk-taking behavior remain poorly understood. Here, we studied risk preferences of chimpanzees (86 Pan troglodytes; 47 females; age = 2–40 years) using a multimethod approach that combined observer ratings with behavioral choice experiments. We found that chimpanzees’ willingness to take risks shared structural similarities with that of humans. First, chimpanzees’ risk preference manifested as a traitlike preference that was consistent across domains and measurements. Second, chimpanzees were ambiguity averse. Third, males were more risk prone than females. Fourth, the appetite for risk showed an inverted-U-shaped relation to age and peaked in young adulthood. Our findings suggest that key dimensions of risk preference appear to emerge independently of the influence of human cultural evolution.

Predictions about reward outcomes in rhesus monkeys.

“…This aligns with prior work on adolescent changes in reward sensitivity in humans (Cohen et al, 2010;Hauser et al, 2015). While there have been few studies of comparative development of reward-based decision making in nonhuman primates (De Petrillo & Rosati, 2021), this finding also adds to emerging evidence that adolescent primates may respond differently to rewards and decision-making contexts than do adults, such as by showing more risk-seeking preferences (Haux et al, 2022;Rosati et al, 2023). Conversely, we did not find evidence here that older monkeys showed any declines in their reward sensitivity as younger and older monkeys showed similar looking patterns, unlike in older human adults.…”

Personality traits, rank attainment, and siring success throughout the lives of male chimpanzees of Gombe National Park

“…Although chimpanzees experience age-related changes in social behavior ( Rosati et al, 2020 ; Thompson González et al, 2021 ) and personality ( King, Weiss & Sisco, 2008 ; Haux et al, 2023 ) resembling aging patterns in humans, studies in both captive and wild chimpanzees suggests that individual behavioral phenotypes are stable ( King, Weiss & Sisco, 2008 ; Weiss et al, 2017 ; Tkaczynski et al, 2020 ; Thompson González et al, 2021 ). Thus, given the present findings of associations between personality traits and fitness, another productive avenue for future studies would be to identify which behaviors related to Dominance and Conscientiousness are responsible for higher rank and reproductive success in males.…”

Observational approaches to chimpanzee behavior in an African sanctuary: Implications for research, welfare, and capacity‐building

“…For example, research at several different Pan African Sanctuary Alliance sanctuaries, including Ngamba Island Chimpanzee Sanctuary in Uganda, Tchimpounga Chimpanzee Sanctuary in Republic of Congo, Sweetwaters Chimpanzee Sanctuary in Kenya, and Lola Ya Bonobo Sanctuary in Democratic Republic of Congo, have used experimental tasks to examine how chimpanzees and bonobos think and solve problems. This has included a large variety of work spanning cooperation and prosociality (Bullinger et al, 2011; Engelmann et al, 2015; Hare et al, 2007; John et al, 2019; Koomen & Herrmann, 2018, 2019; Melis et al, 2006a, 2006b; Rosati et al, 2018; Schneider et al, 2012; Tan et al, 2015; Warneken et al, 2007), social learning (Clay & Tennie, 2017; Herrmann et al, 2007; Horner & Whiten, 2005; Tennie et al, 2012), social cognition (Krupenye & Hare, 2018; MacLean & Hare, 2012), decision‐making (Eckert, Call, et al, 2018; Eckert, Rakoczy, et al, 2018; Haux et al, 2023; Herrmann et al, 2015; Keupp et al, 2021; Krupenye et al, 2015; Rosati & Hare, 2011, 2012b, 2013; Sánchez‐Amaro et al, 2021; Völter et al, 2022), memory (Rosati & Hare, 2012a; Rosati, 2019), and individual variation and developmental change in a variety of cognitive skills (Cantwell et al, 2022; Herrmann et al, 2010, 2010; Herrmann et al, 2011; Wobber et al, 2010; Wobber et al, 2014). These studies typically involve experiments where animals are presented with novel stimuli or problems, such as whether they can discriminate between functional or nonfunctional tools, or how they may work together on an apparatus to obtain an out‐of‐reach treat.…”

“…Second, there have been observations of chimpanzee behavior at both Tchimpounga and Chimfunshi to examine behavioral indicators of these chimpanzees’ welfare, such as the presence of aberrant behaviors like coprophagy (van Leeuwen et al, 2023; Wobber & Hare, 2011). Third, some work has integrated observations with experimental studies at Sweetwaters and Ngamba, such as to examine how social relationships in natural chimpanzee groups impact cooperative performance in experimental tasks (Engelmann & Herrmann, 2016; Engelmann et al, 2019) or used keeper's ratings of risk taking compared with experimental measures of risk assessment (Haux et al, 2023). There has also been relevant observational work with bonobos at Lola Ya Bonobo examining various aspects of behavior, including patterns of consolation and post‐conflict interactions (Clay & de Waal, 2013a, 2013b), juvenile dominance (Walker & Hare, 2016), tool use (Gruber et al, 2010), and patterns of vocal communication (Clay & Zuberbühler, 2012; Clay et al, 2011; Genty et al, 2014).…”