There is an immediate and major problem with a suggestion that religious behaviour
might have evolved. This problem can be summed up by saying, ‘Group-selection’.
Any gene for an adaptation that benefits the group must not disadvantage any individual
bearing it or natural selection will eliminate the gene.
If an individual has altruistic genes then the extra burden of being altruistic will
mean that other more selfish individuals will leave behind more of their selfish
genes. The altruistic genes do not spread - they rapidly become extinct.
Thus group-selection, the idea that a group of organisms could work together to enhance
the fitness of the group, fails by the logic of natural selection - selfish individuals
will leave more of their offspring behind and so the group genes will not spread.
Under the ‘default hypothesis’ this problem is avoided. Individuals are born with
the selfish default mode in operation. They look after themselves as a top priority.
They will only switch to group mode if sufficiently strong group stimuli are present.
The role of justice
Selfish individuals who deceptively display behaviour which allows group membership
but who do not cooperate with the group will sometimes succeed. However, there is
increasing evidence that humans (and other primates) have a strong, innate sense
of justice that sees them act quickly to eliminate such cheats and traitors.
This capacity to exact justice, which is only possible with a brain that is capable
of a high degree of social modelling, tips the balance in favour of the altruists
rather than the selfish individuals. The genes that permit conditional altruism
will be reproduced.
I would suggest that the default hypothesis provides an evolutionary stable strategy.
It prevents the ‘player’ from displaying inappropriate, losing, behaviour. If the
individual is born into a chaotic, non-religious social situation then it will not
engage in group supporting behaviour. However, if it finds that there it is in such
a law abiding social situation then it has the capacity to bond to the group and
so gain the benefits.