Abstract

This thesis investigates the genetic and evolutionary bases of how decisions are made. Specifically, Study 1 examined the genetic underpinnings of decision-making styles by contrasting the relative similarities of monozygotic and dizygotic co-twins along the general decision-mating style and maximizing scales. The results suggest that the extents to which individuals exhibited rational, intuitive, spontaneous and maximizing decision styles were significantly affected by genetics. While the hypotheses pertaining to the dependent and avoidant styles enjoyed directional support, the results were not statistically significant. In Study 2, the predecisional choice processes of monozygotic and dizygotic co-twins were examined in light of the amount, selectivity and pattern of information processing exhibited as twins independently solved a computerized decision-making task. The results suggest that while the amounts of information processed predecisionally were influenced by innate elements of subjects' decision-making personalities, the selectivity and pattern components of the choice process were seemingly adaptive to characteristics of the problem at hand. Finally, in providing a Darwinian analysis of the information search process underlying mate choice, Study 3 sought to demonstrate the evolutionary bases of the mind's adapted cognitive policies. To this end, subjects were asked to find a short-term mate via a computerized mate selection task. In line with evolutionary predictions, individuals tended to deliberate more extensively prior to choosing versus rejecting potential mates. Moreover, females tended to evaluate more candidates than males before identifying a winning suitor and devote more search effort to the task overall. Additional findings and implications are reported in the thesis.