Sekiguchi Takuya, Nakamaru Mayuko
Department of Value and Decision Science, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan.
J Theor Biol. 2011 Feb 21;271(1):124-35. doi: 10.1016/j.jtbi.2010.11.044. Epub 2010 Dec 3.
Individuals tend to conform their behavior to that of the majority. Consequently, an individual's behavior is not always consistent with his or her attitude, and such inconsistency sometimes causes mental distress. Understanding the mechanism of sustaining inconsistency between attitude and behavior is a challenging problem from the viewpoint of evolutionary theory. We constructed an evolutionary game theory model in which each player has an attitude and behavior toward a single social norm, and the players' attitudes and behaviors are affected by three types of cultural transmission: vertical, oblique, and horizontal. We assumed that strategy is a combination of attitude and behavior and that the process of learning or transmitting the social norm depends on the life stage of each player. Adults play a coordination game in which players whose behaviors match those of the majority obtain a high payoff, which is diminished by any inconsistency between attitude and behavior. The adults' strategies are passed to newborns via vertical transmission, and the frequency of a newborn's replication of strategy is proportional to the corresponding adult's payoff. Newborns imitate behaviors of unrelated adults via oblique transmission. Juveniles change their attitudes or behaviors by observing other juveniles' behaviors or inferring other juveniles' attitudes (horizontal transmission). We conclude that the key factor for sustaining inconsistency between attitude and behavior is the ability of players to infer and imitate others' attitudes, and that oblique transmission promotes inconsistency.
个体倾向于使自己的行为与大多数人一致。因此，个体的行为并不总是与他或她的态度一致，而这种不一致有时会导致精神困扰。从进化理论的角度来看，理解维持态度与行为不一致的机制是一个具有挑战性的问题。我们构建了一个进化博弈论模型，其中每个参与者对单一社会规范都有态度和行为，并且参与者的态度和行为受到三种文化传播类型的影响：垂直传播、斜向传播和水平传播。我们假设策略是态度和行为的组合，并且学习或传递社会规范的过程取决于每个参与者的生命阶段。成年人进行协调博弈，其中行为与大多数人一致的参与者获得高收益，态度与行为之间的任何不一致都会降低收益。成年人的策略通过垂直传播传递给新生儿，新生儿复制策略的频率与相应成年人的收益成正比。新生儿通过斜向传播模仿无关成年人的行为。青少年通过观察其他青少年的行为或推断其他青少年的态度（水平传播）来改变自己的态度或行为。我们得出结论，维持态度与行为不一致的关键因素是参与者推断和模仿他人态度的能力，并且斜向传播会促进不一致性。
