Described and critiqued are studies that attempt to describe how personality factors affect foreign policy decision making. Political behavior cannot be explained in terms of personality alone. Such an attempt is a psychological reductionism that ignores the chains of causation that run from underlying personality construct to social and political structures. The paper begins by discussing rational models of foreign policy decision making that have been used in psychological studies. Two other models, the organizational process model and the bureaucratic political model, are then discussed. An examination follows of how I. Destler and A. George, not satisfied with either of the latter two models, chose to combine the two models for a more fruitful explanatory device. How other political writers have concentrated on the president's relationships with his advisers when making foreign policy decisions--a combination of impact analysis and presidential style analysis--is discussed. The paper concludes by discussing the theoretical, methodological, and data problems that plague all these approaches to the study of personality and foreign policy decision making. (RM)