Group selectionism is the minority view among evolutionists that natural selection in humans occurs in the manner of eusocial species, at the level of groups, not just genes. Eusocial species comprise primarily the social insects, whose hives’ genetic commonality permits group selection, which in their case—unlike the human—reduces to the gene level. Social psychologist Jonathan Haidt in his recent book The Righteous Mind (2013) frames the case for human group selection with the aphorism “Humans are 90% chimpanzee and 10% bee.” Haidt observes that most moral arguments are hypocritical, aiming to impress or control others, agents often ignoring standards when they can avoid punishment for transgressions. Yet Haidt acknowledges that humans occasionally behave selflessly, as when a soldier takes huge personal risks for his fellows or zealots lose themselves in moral or political causes. Haidt thinks these phenomena inexplicable at the gene or individual level because it would subject agents to strongly adverse selection pressures, since their altruism fails to serve their individual interests. Group selectionism is subject to a standard objection: inevitable exploitation by free riding, which group-selectionist theory must contain a mechanism to punish. Human societies curtail free riding by social approval and disapproval, including material rewards and punishments.
According to Haidt (and other strict-adaptationist theorists), the proclivity to reward and punish transgression against group interest must arise through group selection because otherwise approval and disapproval meted out in the group interest would be another form of self-sacrifice. The habit theory of morality treats moral approval and disapproval as expressing the same habit set used for self-control, illustrated by the habit theory of civic morality: U.S. citizens practice habits of frugality in their personal lives by demanding the government cut spending. The same equivalence describes moral suasion directed toward individuals.
Ironically, moral hypocrisy provides evidence that self-control and moral suasion practice a unified moral habit. If hypocritical demands are seen as purely deceptive, it’s hard to see how they would serve as a costly signal; carrying no costs, moral hypocrisy would have no value as a signal. Hypocrisy has no point if anyone can be a hypocrite cheaply. But if engaging in moral suasion agents rehearse (practice) principles of integrity that they habitually apply to themselves, the cost of demanding more morality than you want to give is becoming more moral than you wish.
The workings become clearer and more plausible with more concreteness about the structure of the moral habits (or principles of integrity), and Alan P. Fiske’s relationship-regulation theory integrates well with the habit theory. According to Fiske’s model, systems of moral principles are activated when their associated social relationships are “constituted,” where the systems of moral principles are Unity, Hierarchy, Equality, and Proportionality. (T.S. Rai and A.P. Fiske, Moral psychology is relationship regulation (2011) Psychological Review, 118: 57 ‒ 75.) Hierarchical principles, for example, are activated when the appropriate social relations of Authority/Ranking are constituted, so when an agent is involved in an authoritarian relationship, such as between employees and their boss, the corresponding Hierarchical principles of unconditional submission and conditional protection dominate. To restate in habit-theory terms, negotiating hierarchical relationships motivates agents to form habits based on Hierarchical principles. Most importantly, the Hierarchical structure is a coherent whole, including facets involving regulation of both self and others. In the habit theory, other-directed morality is a spandrel deriving from the primary adaptive value of self-control.