Non-human primates used in research have the most complex welfare needs of any laboratory animal and require sophisticated social and environmental conditions.
Non-human primate welfare in laboratories represents the highest complexity case in animal research ethics. Their cognitive abilities, social sophistication, and capacity for emotional suffering are well-documented and comparable in some dimensions to humans. Isolation causes severe psychological deterioration manifest in self-injurious behavior, depression, and stereotypies. Even with social housing, the cognitive demands of intelligent animals require substantial environmental complexity to prevent boredom and frustration. The scientific and ethical case for minimizing primate use through alternative methods is stronger than for any other laboratory species, alongside continuous refinement of conditions for those still used.