title: Genetic Factors of Individual Differences in Decision Making in Economic Behavior: A Japanese Twin Study using the Allais Problem.
abstract: Why does decision making differ among individuals? People sometimes make seemingly inconsistent decisions with lower expected (monetary) utility even when objective information of probabilities and reward are provided. It is noteworthy, however, that a certain proportion of people do not provide anomalous responses, choosing the alternatives with higher expected utility, thus appearing to be more "rational." We investigated the genetic and environmental influences on these types of individual differences in decision making using a classical Allais problem task. Participants were 1,199 Japanese adult twins aged 20-47. Univariate genetic analysis revealed that approximately a third of the Allais problem response variance was explained by genetic factors and the rest by environmental factors unique to individuals and measurement error. The environmental factor shared between families did not contribute to the variance. Subsequent multivariate genetic analysis clarified that decision making using the expected utility theory was associated with general intelligence and that the association was largely mediated by the same genetic factor. We approach the mechanism underlying two types of "rational" decision making from the perspective of genetic correlations with cognitive abilities.
authors.affiliation: Department of Psychology, Faculty of Liberal Arts, Teikyo University Tokyo, Japan.
authors.forename: Chizuru
authors.initials: C
authors.lastname: Shikishima
authors.affiliation: Faculty of Letters, Keio University Tokyo, Japan.
authors.forename: Kai
authors.initials: K
authors.lastname: Hiraishi
authors.affiliation: Faculty of Arts and Science, Kyushu University Fukuoka, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamagata
authors.affiliation: Faculty of Letters, Keio University Tokyo, Japan.
authors.forename: Juko
authors.initials: J
authors.lastname: Ando
authors.affiliation: Faculty of Letters, Keio University Tokyo, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Okada
keywords: Allais problem; behavioral genetics; cognitive ability; decision making; expected utility theory; prospect theory; twin