The field of law and psychology has existed, in some form or another, for almost 100 years. The article presents a brief overview of law and psychology in the last century and shows that there actually have been two movements-one in the first third, and the other in the latter third, of the century. Given these movements, why has the law and psychology movement had so little impact on the law (and, for that matter, on psychology)? Failure to ponder-and answer-this question, may result in the demise of the movement. Given the power of law over individuals and societies, though, the application of psychology to the law is an important and useful way to assess the validity of laws and to ensure that psychological research can influence the law. This paper discusses 12 reasons that may have contributed to the relative failure of the law and psychology movement thus far. In presenting each of the reasons, and considering factors that have led to some successes in the field, the paper discusses methods and strategies that may help ensure the continued vitality and strength of the field of legal psychology.The development of the synthesis of law and psychology will be a long and perhaps a tedious process; but it is a process, however much patience it may require, which for the law will yield a fruitful harvest (Cairns, 1935, p. 219).