Roughly, religion is a community's costly and hard-to-fake commitment to a counterfactual and counterintuitive world of supernatural agents who maste… - Scott Atran

One such evolutionary system, or ridge, encompasses panhuman emotional faculties, or affective "programs." These include the basic, or primary, emotions that Darwin first identified: surprise, fear, anger, joy, sadness, disgust, and perhaps contempt. Certain reactions characteristic of the neurophysiology of surprise and fear are already evident in reptiles, and the other primary emotions are at least apparent in monkeys and apes. Then there are the secondary, mostly "social" emotions, such as anxiety, grief, guilt, pride, vengeance, and love. These may be unique to humans-hence, at the lower level in our evolutionary mountain landscape and somewhat more liable to cultural manipulation and variation than the primary, "Darwinian" emotions. Thus, only humans seek revenge or redemption across lifetimes and generations, whatever the cost, although the nature of the deeds that trigger insult or remorse may vary considerably across societies, and the means to counter them may range even wider.

Religious ritual survives cultural transmission by embedding episodes of intense, life-defining personal experiences in public performances. These performances involve sequential, socially interactive movement and gesture (chant, dance, murmur, sway) and formulaic utterances that rhythmically synchronize affective states among group members in displays of cooperative commitment. This is often accompanied by sensory pageantry, which further helps to emotionally validate and sustain the moral consensus.

Another ridge includes social interaction schema. Some of these schema may have aspects that go far back in evolutionary time, such as those involved in detecting predators and seeking protectors, or that govern direct "tit-for-tat" reciprocity (you scratch my back, and I'll scratch yours; if you bite me, then I'll bite you). Other social interaction schema may have elements common to some species of social mammals (e.g., bats, wolves, monkeys, and apes). Examples include certain systematically recurrent forms of delayed reciprocity (you help me now and I'll help you later), indirect reciprocity (I'll help those who help those who help me; the enemies of my enemies are my friends), and greeting displays of submission-domination. Still other social interaction schema appear to be unique to humans, such as making decisions to cooperate on the basis of social signs of reputation rather than on the basis of individual observation and experience, or in offering and obtaining future commitments of an indeterminate nature (when the chips are down, I'll help you, whatever the situation). Only humans, it appears, willingly commit their lives to groups of nonkin.