Character matters. Presidents cannot escape being themselves. Their character shapes their beliefs and behaviors and conditions their relationships with others. It is not the only factor that affects their thinking, speaking, deciding, and interacting, but it is relatively constant and almost always relevant. Winning candidates do not discard their personalities when they enter the White House. Traits that they exhibited in the past affect their current behavior and anticipate their future thoughts and actions. That is why the study of presidential character and its derivatives, beliefs and style, are so important.
The growth in the power of the presidency, the reach of a president's decisions and actions, and the impact they can have all over the world make it essential to examine character and the ways in which it can and does influence policy making and implementation. The problem, however, is that the goals of contemporary political science research and its quantitative modes of analyses are not well suited for the examination of complex, and somewhat idiosyncratic, case studies, particularly those in which personality traits are inferred from observable behavior and then used to explain particular outcomes and anticipate others that might occur in similar situations.
The presidential decisions and actions in which character is likely to play a larger role are those that tend to be the most important and controversial; they also tend to be the most complex with many interrelated variables potentially affecting the final decision. The character of the president, the external environment, the particular situation, and the timeframe for the decision must also be considered. It is difficult to identify all these variables, much less discern their individual and collective impact on decision making.
But political scientists want to do more than understand a single decision. They want to provide a broader explanation of how a president or presidents decide; they also would like to anticipate future decisions. To achieve this objective, they need to generalize. A single case study cannot be the basis for a generalization. Comparative case studies are necessary. To facilitate comparison, idiosyncratic details must be excluded. But when they are, the comparative cases may lack external validity if those factors, independently or collectively, affected the final outcome. External validity versus comparability is the trade-off social scientists must make when designing their research projects. The more detail they include, the more likely the case will reflect the real world, but also the more difficult it will be to generalize from one decision or action to another.
That said, however, ignoring the influence of character on judgment and performance because the discipline of political science finds it difficult to study flies in the face of conventional wisdom that people can and do affect the decisions they make and the actions they take. It also ignores a body of psychological literature that postulates theories of personality on the basis of clinical observation, experimental design, psychometric measurement, social interaction, organizational leadership, and environmental influences on individual and group behavior. Finally, it neglects a newer area of research in which genetic components of attitude formulation and political activity are being identified and measured.
Studies of character, however, have their research problems as well. One stems from the psychological inferences drawn from observable behavior. Such inferences, even those based on psychological theory, are inherently speculative. Another difficulty results from the specification of particular psychological facts on performance. If situational and environmental variables are not considered or are not constant, the outcome may be different even though the character of the person making the decision or taking the action has not changed. …