Reflections on the first decade of the HIV/AIDS pandemic: opportunities and priorities for international behavioural research and interventions.

AIDS, a sexually transmitted disease, is unlikely to respond in the near term to either common sense or scientific innovation. Other forces are at play here that embrace the psychobiology of reproduction, addictive behaviour, and the social sciences. We must explore these matters within the historical and cultural context. We must push to the limit the science of behaviour and behaviour modification. To meet this challenge, the social and behavioural sciences and the natural sciences must form a new union in which the sum is greater than the parts. The integration of population biology into research strategies will require special attention. Planning the design and employment of interventions and the evaluation of their effects will require the use of mathematical models. Efforts to change individual and social behaviour must be tailored to the cultural circumstances of the afflicted populations. None of this will be easy. But the changing sexual behaviour among homosexual men and the increasing use of condoms by prostitutes and their customers in many societies stand as testimony to the power of public efforts.