Social hierarchy influences monkeys' risky decisions.

Primates' decision-making in economic contexts follows distinctive patterns, as initially described by Prospect Theory. Social animals, such as monkeys, live in hierarchically structured groups where individual status may influence cognitive processes, including economic decisions. We leveraged a unique dataset from a semi-free ranging macaques' group, which had continuous access to gambling tasks over several years, yielding hundreds of thousands of trials and longitudinal assessments of social hierarchy. Our findings reveal a dynamic relationship between social hierarchy and decision parameters: middle-ranking individuals displayed reduced risk aversion for potential gains but not losses. Longitudinal analyses suggested that changes in social rank were followed by corresponding shifts in risk attitudes, implying that social position, rather than inherent traits, influences decision-making patterns. While sex had no significant impact, age was primarily associated with variations in loss aversion. These results underscore the flexibility and adaptive nature of primates' cognitive biases and provide key insights into how social structures influence risk behavior, with potential implications for understanding decision-making processes in other social species, including humans.