Primates are among the most socially complex zoo animals. Appropriate social housing is a fundamental welfare requirement that many zoos still fail to meet.
Primate social needs cannot be addressed through any amount of physical enrichment, dietary variety, or keeper attention. These animals evolved their extraordinary cognitive abilities in the context of complex social relationships - to navigate alliances, remember individual histories, and engage in cooperative and competitive social strategies. Depriving a chimpanzee, gorilla, or macaque of appropriate social companionship is to deprive them of the context in which their minds evolved to function. A solitary primate, no matter how well-fed or physically healthy, is experiencing a profound welfare deficit. The logistical challenges of managing primate social groups are real but they are the responsibility of institutions that choose to house these animals.