Common marmosets are increasingly used in biomedical research as an alternative to larger primates, with welfare challenges from their highly social nature and complex needs.
Marmosets used in research isolated from conspecifics or housed in barren environments show stereotypic behaviour, self-directed aggression, and social dysfunction. Their cooperative breeding system means that group living with multiple individuals is necessary for normal developmental and psychological wellbeing. Research procedures that require individual housing should be as short-term as possible with appropriate social housing between procedures. The use of marmosets in neuroscience and toxicology research involves procedures causing acute and chronic suffering that requires welfare justification.