Primates used in biomedical research have complex social and cognitive needs. Social housing standards are among the most impactful welfare improvements available in laboratory settings.
Primate welfare in research settings depends critically on social housing and behavioral management. Macaques housed alone show elevated cortisol, abnormal behavior, and disrupted sleep — all indicators of chronic stress. The requirement to justify isolation rather than justify socialization represents a meaningful regulatory shift that has improved conditions for many animals. However, compliance varies across institutions and social housing requires skilled management to prevent injury from incompatible animals. Marmosets can be housed in family groups that provide naturalistic social environments. The 3Rs framework applied to primates emphasizes both reduction of animal numbers and refinement of conditions for those used. Increasing non-primate alternatives continue to reduce demand.