offspring. We have already mentioned three solutions to this kind of problems:
kin-selection, reciprocal altruism, and group-level selection. Among these
solutions, reciprocal altruism can be seen as an adaptation at the level of the
organism. Exchanges with gods often follow the logic of tit-for-tat, in which
the human partner brings offerings to secure the goodwill of the gods, spirits,
or ancestors (who are actually thought to benefit from the sacrifice; see Boyer,
2001, pp. 229–30). Individuals do not necessarily always engage in reciprocal
exchange with the same cooperation partner. Helping someone and then
being helped by someone else is made possible byreputation management
(Nowak & Sigmund, 2005): in small-scale societies (and friendship networks),
an individual’s record as a reliable cooperation partner is an important asset
that can directly increase one’sfitness. If religious faith is associated with
moral commitment (such as in Matt. 22:37–40), reputation management can
be centered on how religious people are (Atran & Norenzayan, 2004, p. 716).
For example, a recent study has shown that people in the United States
exaggerate their own religiosity (such as they report attending more Church
services than they actually do), most likely because religiosity in the US has
been“traditionally associated with morality and pro-social behavior”(Cox et al.,
2014, p. 4). Another adaptation for cooperation is the cognitive capacity of
cheater detection, that is, the ability to recognize individuals who take advan-
tage of cooperation partners (Ermer et al., 2007). Gods and spirits are believed
to detect cheating; in fact, they have access to people’s true intentions and
predispositions beyond what is available to other humans.
Other basic elements of morality could evolve genetically in small-scale
societies, such as feeling guilt after causing harm (as measured by one’s own
standards) to others, or as a precautionary signal while just contemplating
such actions. Evolutionary psychologists assume (Barkow et al., 1992, p. 214;
Krebs, 2005; Dunbar & Barrett, 2007, p. 8) that ostracism was a major tool to
discipline anti-social behavior in the ancestral human groups (as indeed it has
been found to serve such a purpose in contemporary hunter-gatherer soci-
eties), which would mean certain death by predators or starvation.^7 Under
such circumstances, guilt could serve as a warning signal that prevented the
individual from running into trouble. One could easily provide religious
explanations for such feelings, attributing antisocial drives to demonic influ-
ence or abstract concepts such as original sin, or attributing guilt to the
influence of a deity who sees one’s inner thoughts and intentions
(e.g., Rom. 1:18–32; 7:7–25). Note that while punishment is a group-level
(^7) Note that modern hunter-gatherer societies are not pre-historic fossils and there is great
variation in their social and justice systems. A quick search in the eHRAF database indicates that
ostracism (as well as direct execution) is practiced in hunter-gatherer societies across the globe
(e.g., Turnbull, 1965, p. 186; Metge, 1995, p. 277).
Evolution 37