Reinhardt, V. 1989. Alternatives to single caging of rhesus monkeys. Humane Innovations and Alternatives in Animal Experimentation 3, 123-125.

Single-housed rhesus macaques were transferred to permanent pair-housing arrangements. The present investigation also demonstrates that pairing caged rhesus monkeys with compatible conspecifics does not interfere with a number of common research protocols [e.g., headcap implantation, experimental surgery, blood collection]. Our experiences even suggest that distress related to handling or restraint is reduced by the presence of the familiar companion.