When I hear the words “evolution” and “religion” in the
same sentence, my immediate instinct is to cringe at the classic conflict
between creationist and evolutionary perspectives that has pervaded Western
society and American courtrooms, starting with the historic Scopes Monkey
Trial. But there is an even more far-reaching and bracing relationship between
evolution and religion, with the field of evolutionary psychology bridging the
gap between these two worlds. Evolutionary psychology seeks to identify causal
mechanisms for psychological phenomena, using evolutionary processes as a
foundation for explaining human behavior. Religious belief is one of the most
common elements of human culture, with nearly every modern civilization having
some sort of supernatural belief system in place.
Evolutionary
psychologists agree that there must be an evolutionary basis for religion, an
almost universal element of human society, apart from the actual existence of
supernatural beings. However, they have not been able to reach a consensus
about the specific evolutionary significance of religion. Considering the
various forms of interpersonal cooperation, sharing of resources, and mutual
conflict that often result from religious belief in society, is religious
belief best explained as a direct adaptation for social exchange or an indirect
exaptation, or byproduct? Evolutionary psychologists have proposed several
theories to explain why religion developed and gained prevalence as a part of
human societies, including its adaptive significance for individuals and
groups, as well as a byproduct of other social mechanisms. Of these, the group
selection model seems the most plausible, as it clearly explains how religion
could improve the fitness of a group or society and why this trait would have
evolved by natural selection.
Religion is a nuanced, complex concept that requires a
clear definition before one can hope to explain its evolutionary significance.
In general, religion can be defined as a system of beliefs in supernatural
agents with some degree of omniscience and/or omnipotence. Religion must be
shared between individuals, resulting in communal beliefs and practices. In
social contexts, it acts as an organizing force for believers, and involves
some sort of social stratification to give elevated status to religious
leaders, like shamans or priests. As a part of its social nature, it also
requires that individuals participate in rituals that involve altruism, such as
sacrificing one’s livestock for the gods (Bulbulia 2004). By this definition,
belief in a supernatural power is not sufficient to qualify as religion. The
system of beliefs must be shared and must induce some form of ritual commitment
that lowers an individual’s own fitness for the sake of the group (religious
altruism).
In
order to view religion from an evolutionary perspective, one must define an
‘ancestral’ and a ‘derived’ state that can draw a line between the historical lack
and presence of religion in society. It is hard to find a historical example of
the ancestral state, as religious belief is essentially universal among
hunter-gatherer societies and modern civilizations alike (Bulbulia 2004). If
the derived state is defined as an organized, shared system of supernatural
beliefs that fulfills all of the conditions listed above, then the ancestral
state can refer to the lack of an organized set of beliefs that is shared
within a community. For instance, a prehistoric population of Neanderthals who,
despite having some predisposition to believe in the supernatural, had not yet
organized or codified a set of beliefs common to their community, would still
be considered to be in the ancestral state. Then the derived state, religion,
cannot exist without the social aspects of rituals and stratification.
Specifically, religion can be described as mediator of
social exchange, in that it entails moral principles and ritual practices that
govern interpersonal relations in religious communities. Supernatural agents
may directly govern some aspects of social exchange, as many religions invoke
gods that “police social contracts” (Bulbulia 2004). In short, religion
promotes the morality of followers through the intrinsic reward and punishment
mechanisms of the gods. Bulbulia additionally argues that “costly religious
displays convey information that solves prisoner’s dilemmas,” and that this can
account for the omniscience and omnipotence of gods (Bulbulia 2004). Basically,
rituals like celibacy and self-sacrifice harm an individual’s personal fitness
(giving them a ‘handicap’) in order to demonstrate commitment to a religion.
Participation in these rituals involves altruism, and is thus subject to the
‘prisoner’s dilemma,’ in which an individual must essentially decide between
altruistic or cooperative actions and selfishness, based on the possible
effects on his/her fitness. Religion’s many complex effects on social exchange
have prompted three major explanatory theories of its evolutionary significance.
Some adaptationists have argued that religious commitment
can improve an individual’s fitness when he/she is part of a community of other
believers, and is thus subject to natural selection at an individual level.
Belief in supernatural agents can “alter the relevant payouts for exchange” in
social contexts (Bulbulia 2004); omniscient gods cause individuals to be
morally accountable. If a believer defects from his commitment, he may risk
punishments sometimes as severe as eternal damnation for acts of selfishness.
If religion is an adaptation, it must have evolved to solve a particular
ancestral ‘problem,’ and it must satisfy the four postulates of natural
selection. Religious belief and commitment must vary between individuals, this
variation must be heritable, the fitness (survival and reproductive success) of
individuals must vary, and the heritable variations in religious belief must
affect an individual’s fitness. The individual adaptation model proposes that
religion fulfills these requirements by fostering cooperation and reciprocal
altruism, as well as individual benefits for religious believers. Clearly,
individuals show variation in their levels of religious belief, degrees of
commitment to social exchange, and in the types of reward and punishment
systems in which they believe. Heritability, in this model, is slightly more
complicated. Individuals inherit the innate psychological mechanism of
cost-benefit analysis of actions, through basic socialization processes. They
also acquire knowledge of the costs and benefits of certain actions, which can
be passed on through cultural inheritance. Fitness varies in the sense that
those who are more strongly committed to social exchange forfeit more material
resources, but in their minds, see themselves as achieving the immaterial
success of salvation (reward), as opposed to damnation (punishment). Therefore,
an individual who is more committed to social exchange will be more positively
rewarded within a religious framework, and will not incur a significant loss of
material resources if surrounded by other religious people.
This
framework, though it accounts for why individuals may be inclined to believe,
does not provide a clear reason why this would increase their fitness relative
to nonbelievers. Natural selection can only act upon phenotypic differences in
success while living, not on mental pictures of eternity. Even if an individual
believes that he/she will be granted eternal salvation, this will not
positively affect physical survival or reproductive success. In fact, the
individual will probably incur a loss from his altruistic actions, which would
decrease fitness and cause selective pressures to act against religion. There
is no clear reason that natural selection would favor an individual who is less
selfish, even if the individual himself believes that he is increasing his
fitness. The model does explain why being surrounded by other religious and
altruistic individuals would increase success, but does not explain why
religion would persist among individuals rather than be eliminated completely.
Theoretically, a non-religious person would have the highest fitness in a
religious community, because he/she could partake of others’ resources without
giving up any of his/her own resources in return (Bulbulia 2004).
Many, like me, are dissatisfied with this account of
natural selection for religious belief, and instead look to its adaptive
benefits at the group level. David Sloan Wilson is a proponent for group
selection: the view that natural selection can act on groups, just as it acts
on individuals, through differences in group fitness and inter-group
competition (Wilson 2002). He argues that “the best explanation for religious
thought and behavior is that it facilitates strongly integrated and functionally
adaptive groups” (Bulbulia 2004). The group adaptation model seeks to explain
non-reciprocal altruism, such as non-violence, vegetarianism, charity, and
other forms of sacrifice, as beneficial adaptations for the survival of groups.
Group selection models argue that the increased fitness of religious groups as
units can overrule the decreased fitness of individuals within a group. In
other words, strong positive selection for religious altruism at the group
level can preserve religion even if individual selection favors selfishness. The
existence of religious ritual could improve the mutual coordination of groups,
thus rendering them more successful than non-religious groups.
Again,
this model must be examined in relation to the four postulates of natural
selection, this time viewing religious groups as the unit of selection rather
than individuals. Groups show variation in their religiosity (ranging from
devout to secular), as well as the relative number of altruistic rituals that
members of the group are expected to perform. Heritability is still social and
cultural in nature: religious heritage is passed down vertically between
generations and horizontally to other groups of individuals (via proselytism).
Certainly, some groups are more successful than others, in terms of economic
success, survival, et cetera. Richard Sosis conducted an analysis that showed
that “religious communes are more likely than secular communes to survive at
every stage of their life course” (Sosis 2000). Religious communities are more
likely to foster intragroup cooperation and loyalty than their secular
counterparts, which gives them higher fitness. In addition, for religious
communities, having more ritual requirements is correlated to having a longer group
lifespan (Sosis & Bressler 2003). This implies that the effects of
religious ritual on social exchange are highly beneficial to a group’s fitness.
The same trend, however, does not apply for non-religious rituals (for
instance, hazing in modern fraternities) in secular communities (Sosis &
Bressler 2003). This is very interesting, because it indicates that altruistic
behavior on its own is not sufficient to make a group more successful. In
addition, religious communities that do not invoke religious altruism are not
very successful either. The communities that participate in religious altruism
are far more successful; religious altruism is the group trait that would
theoretically be selected for.
The evidence for the adaptive benefits of religion and
ritual on a group level seems very convincing. However, there are some concerns
with the group selection model of religion that deserve some attention.
Religion on a group level can only be explained by group selection, and comes
into conflict with the concept of inclusive fitness, by which individuals seek
to increase their fitness by helping the survival of their relatives. Religious
families as a whole will often risk their well-being for religious commitment
(Bulbulia 2004). However, the whole basis of the group selection argument is
that selection at the group level can act against selective pressures at the
individual level. Also, it is not certain how a sociological adaptation would
appear in individual psychology (Bulbulia 2004). Shared religious belief would
somehow have to appear within several individuals of a group in order for
selection to act upon the group. Perhaps groups of early humans who happened to
begin sharing their supernatural beliefs with each other better withstood the
tests of time, eventually causing organized religion to form. Another slight
complication arises from the levels of stratification within religion:
“religious groups” are hard to define (Bulbulia 2004). In a modern sense, this
could refer to individual churches, sects, denominations, whole religions, or
even the entire community of ‘believers’ in the world. Though it does make it
harder to characterize the effects of group selection, it’s plausible that
selection is occurring at several or all of these levels, according to the
different selective pressures acting at each level.
However, there are others who remain unconvinced that all
of the effects of religion on social exchange can be explained by a single
adaptive mechanism, and argue instead for religion as a byproduct of other
psychological phenomena. Gould & Vrba term these byproducts “exaptations,”
in which an original adaptation is co-opted to a second purpose after it
evolves, conferring increased fitness (Gould & Vrba 1982). Some
evolutionary psychologists observe that religion is not a necessary component
of group sociability, and that groups divided along secular lines, such as
ethnicity, sex, or political affiliation, produce similar results (Bulbulia 2004).
Therefore, group-oriented sociability could have evolved independently, and
then become co-opted as a mechanism for supporting religion in society. However,
this seems less likely in light of Sosis and Bressler’s analysis. Secular
groups that imposed altruistic requirements on their members were not
significantly more successful than other secular groups, and religious groups
that did not invoke religious altruism were not much more successful than
secular groups. From an evolutionary perspective, religion seems to coincide
directly with group sociability, rather than one preceding the other.
Another
concern is that religion does not always control morality: “large societies are
more often characterized by a belief in moralizing gods…[and] religious beliefs
are correlated with existing social relations in a given society” (Roes &
Raymond 2002). In other words, moral pressures coincide with the existing
social structure of society; hunter-gatherer religions did not involve religious
moralism or economic stratification between shamans and laymen. Therefore,
religion may not have initially evolved with a moral agenda, or to enforce
social contracts. However, even if religions are shaped to the societies from
which they arise, and not vice versa, religious altruism would still play a
major role in the success of the societies’ social structures over time.
Ancient religious groups still involve religious altruism in the form of
rituals, and thus could still differ in group solidarity and functionality.
Clearly, none of the theories presented thus far are
foolproof, and all require further investigation. However, the group selection
model provides a clear and logical explanation for why scattered beliefs in the
supernatural would evolve into organized religion, in the context of altruistic
rituals. The individual selection model does not really show how individual
religious believers would have increased fitness over non-believers in a group.
The group selection model, by contrast, develops religious ritual as an
adaptation for group success, and implies that religion evolved for the purpose
of facilitating religious rituals, which in turn act to facilitate successful
social exchange and increased group fitness. It is now for you, the reader, to
consider that ritual altruism could be the real evolutionary purpose of a
system so complex and so important to nearly every human civilization:
religion.
