Non-human primates used in research require complex enrichment to meet their sophisticated social, cognitive, and behavioral needs. Enrichment is both a legal requirement and a scientific necessity.
Non-human primates are among the most cognitively complex laboratory animals, and their welfare needs are correspondingly demanding. Isolation, barren housing, and lack of social interaction cause profound psychological suffering — depressive behavior, self-biting, hair plucking, and rocking are all described in laboratory primate populations. These welfare failures also compromise research: stressed, psychologically abnormal animals produce less reliable data. Meaningful enrichment — social housing above all, combined with foraging complexity and cognitive challenge — is not a luxury but a scientific and ethical necessity. Its consistent implementation should be a prerequisite for any primate research program.