Modular Morals: The Genetic Architecture of Morality as Cooperation

Is morality the product of multiple domain-specific psychological mechanisms or one domain-general mechanism? Recent research suggests that morality consists of a range of solutions to the problems of cooperation that are recurrent in human social life. According to the theory of Morality as Cooperation (MAC), this involves at least seven types of cooperation, giving rise to seven types of morality: Family, Group, Reciprocity, Heroism, Deference, Fairness and Property Rights. However, how genes and environments influence these morals is unclear. Here we use multivariate analysis of a large twin sample (N = 1,066 pairs) to determine the genetic and environmental structure of moral values as measured by the Morality as Cooperation Questionnaire, contrasting models in which these morals are the product of either 1) multiple domain-specific psychological mechanisms versus 2) a single domain-general mechanism implementing all forms of cooperation. The results supported multiple heritable moral mechanisms, and models with fewer than the predicted seven factors fit poorly. A domain-general mechanism was also needed, though this showed non-significant heritability and may reflect response bias. We discuss the current study's limitations and suggest future research on the nature, structure, and content of morality.

道德是否为多个领域特定心理机制的产物，抑或是一般领域机制的单一体现？近期研究指出，道德构成了解决人类社会生活中反复出现的合作问题的多种方案。根据道德作为合作（MAC）理论，这至少涉及七种合作类型，从而衍生出七种道德类型：家庭、群体、互惠、英雄主义、顺从、公平以及财产权。然而，基因和环境如何影响这些道德规范尚不明确。本研究采用对一大样本双生子（N = 1,066对）进行的多变量分析方法，以道德作为合作问卷测量的道德价值观为依据，对比了以下两种模型：1）这些道德规范是多个领域特定心理机制的产物；2）单一领域一般机制实施所有形式的合作。研究结果表明，存在多种可遗传的道德机制，且包含少于预测的七种因素的模型拟合效果较差。尽管如此，仍需一个领域一般机制，尽管这一机制显示出非显著的可遗传性，可能反映了响应偏差。我们探讨了当前研究的局限性，并建议未来对道德的本质、结构和内容进行深入研究。