Motivational Bases of Sex Differences in Choice Behavior: SEX DIFFERENCES IN CHOICE BEHAVIOR MOTIVATIONAL BASES OF CHOICES IN A PRISONER'S DILEMMA HYPOTHESES METHOD SUBJECTS APPARATUS PROCEDURE STRATEGIES DESIGN RESULTS ANCILLARY RESULTS TWO-ALTERNATIVE MATRIX SIX-ALTERNATIVE MATRIX ALTERNATIVE DEFINITIONS OF COOPERATION DISCUSSION REFERENCES

Previous studies comparing male and female choice behavior in a prisoner's dilemma game (PDG) have often confounded contingency of strategy with level of cooperation. Also the motivational basis of the choices was often unclear. A standard PDG and a six-alternative matrix, which separated the various motivations for making the noncooperative alternative, were employed. The subjects, 64 males and 64 females, played under one of four simulated strategies created by crossing two levels of cooperation with two levels of contingency. There were no sex differences under the PDG but there were under the six-altemative matrix. Females, in comparison to males, chose the maximum absolute gain alternative more and the minimize risk alternative less. The results were used to clarify the research on the generalizability of game-playing behavior to other settings.