Psychological wellbeing in zoo animals encompasses cognitive engagement, emotional states, and the ability to exercise agency - dimensions that go beyond physical health metrics.
Psychological welfare in zoo animals requires a conceptual shift from managing physical health to actively supporting positive mental states. An animal that is physically healthy but bored, frustrated, fearful, or cognitively under-stimulated is not experiencing good welfare. The Five Domains model explicitly addresses mental state as a welfare domain, and implementing it genuinely requires zoos to invest in species-appropriate cognitive challenges, choice and control mechanisms, social complexity, and naturalistic environments that provide unpredictability and novelty. The welfare ambition is not merely to eliminate stereotypies but to enable animals to experience positive states - curiosity, play, satisfaction, and social affiliation - that represent flourishing rather than merely the absence of suffering.