Psychological welfare in captive primates requires specific attention to cognitive stimulation, social complexity, and agency.
Captive primates without control over their environment develop learned helplessness, stereotypic behaviors, and self-injurious behavior reflecting chronic psychological suffering. Agency through foraging enrichment, choice in social interactions, and positive reinforcement training restores a sense of control. The psychological complexity of primates means that meeting physical needs without addressing cognitive and social complexity leaves welfare seriously incomplete.