Good social science can greatly enhance environmental design. But whilst some social science research is good, much is bad. The bad examples are very dangerous in that they foist false conclusions onto unsuspecting environmental designers. Therefore, rather than simply accept all social science findings uncritically, it is vital that designers know how to distinguish between work that is good and work that is misleadingly bad. This paper provides a few pointers. It uses, by way of an example, social scientists' attempts to validate a widely-accepted principle.