There are difficulties in performing experiments where human subjects are concerned, and where the theories deal with rather intangible phenomena. The laboratory setting makes most subjects uneasy, and this often interferes with what the experimenter hopes would be normal reactions to experimental stimuli. Experiments on humans are not impossible, but they are difficult, and require a deal of ingenuity and persistence. The Experimental Study of Freudian Theories, have concentrated on what are supposed to be the experiments most supportive of Freudian theories, pointing out the methodological and statistical fallacies involved. And the neglect of alternative theories to explain the results, a failure which is characteristic of much of this literature. This chapter discusses some of the more interesting and memorable research that has been done, mainly to indicate the ways in which psychologists have tried to get round the difficulties inherent in the experimental approach.