In the mixed motive game, The Prisoner's Dilemma, cognitive game, the prisoner's variables (such as abstractness, verbal ability, and quantitative ability), along with individual personality traits, such as altruism, acquiescence, anti-police attitudes, faith in human nature and machiavellianism) are examined in order to measure, under game conditions, a prisoner's decision to cooperate with the authorities. The basic assumption is that two criminals, taken into custody, are placed in two separate rooms without opportunity for communication. The district attorney believes they have both committed a serious crime, but he does not have enough evidence to convict them without a confession. He tells the suspects that if neither of them confesses, he will send them both to jail for a short period of time on some minor charge. If they both confess, they will both be prosecuted and the district attorney will arrrange for them to get less than the maximum sentence. If only one confesses, the confessor will be set free for turning State's evidence, while the silent suspect will receive the maximum sentence. From the prisoners' viewpoint, the optimum solution would be unmatched confession; whereas from a collective viewpoint the best solution would be for both to remain silent and receive a short jail sentence. From the authorities', viewpoint, the best solution would be confession by both. Various types of analytic approaches are used to score the players in this game, including mathematical approaches. Appendixes give research instruments and analysis-of-variance-summary tables. Seventy-four references are appended.