Self-harm in laboratory-housed primates: where is the evidence that the Animal Welfare Act amendment has worked?

The 1985 amendment to the United States Animal Welfare Act (AWA) to promote psychological well being of primates in the laboratory represents an acknowledgment of an important welfare problem concerning nonhuman animals. How effective has this amendment been? Perhaps the best-known contributor to psychological distress in primates in the laboratory is nonsocial housing; yet, available analyses suggest that little progress has been made in avoiding single-caging of these animals. Another way to assess psychological well being is to examine rates of self-abusive behavior in laboratory primates. If the AWA has been effective, then post-AWA self-harm rates might be lower than pre-AWA rates. However, when we attempted to determine those rates from published studies, data were too sparse to allow a rigorous statistical analysis; of 139 studies reporting primate self-harming behavior, only 9 contained data allowing estimation of self-harming behavior rates. We conclude that the current system of laboratory animal care and record keeping is inadequate to properly assess AWA impacts on primate psychological well being and that more is required to ensure the psychological well being of primates.