Lay Personality Theories in Interactive Decisions: Strongly Held, Weakly Supported

In interactive decisions, cues to what others will do are important in forming a strategy. Information about others' personalities appears to be potentially valuable for this purpose. We report a series of four studies examining how information about another actor's personality influences people's own choices in interactive decisions. The studies found widespread beliefs that others' personality characteristics are strongly predictive both of broad classes of decision behavior (competition/cooperation, risk-seeking/risk-aversion) (Study 1) and of specific choices (Study 2) in single-agent settings. These beliefs extended to predicting others' choices in interactive decisions (Study 3) and to shaping the predictor's own decisions in interactive play in Chicken and Assurance games (Study 4). Overall, we found extensive evidence that laypeople believe that the personality traits we selected (angry-hostility, anxiety, assertiveness, excitement-seeking, and warmth) have substantial effects on behavior in interactive decisions and they act on those beliefs when making their own decisions. The empirical evidence supporting the predictive validity of these traits was, however, quite weak.