Reciprocity evolves more readily in competitive than cooperative socio-ecologies

Tracking what others did and matching other’s expected actions is seen
across a range of biological systems. As reciprocal matching rewards and
reinforces cooperators and punishes and discourages non-cooperators,
reciprocal matching can help communal living. The strength of reciprocity
as a social strategy also comes from its success in protecting the
individual against the risk of exploitation by punishing defectors.
Although often overlooked, this feature carries a strong weight when
exploitation risk is high. Here, we use evolutionary agent-based
simulations to examine how reciprocal matching evolves across competitive
socio-ecologies with a high risk of exploitation and cooperative
socio-ecologies with a lower risk of exploitation. Results show that
reciprocal matching as a social strategy for communal living evolves more
readily in more competitive socio-ecologies where risk of exploitation is
high. Results also hold in standard prisoner’s dilemmas with its
equilibrium in single strategies (i.e., unconditional non-cooperation),
for specific forms of reciprocity (i.e., tit-for-tat), and likelihood of
repeated interactions. Because reciprocal matching requires some capacity
for social perception and memory, these findings suggest that such
capacities for social cognition likewise serve to protect against
exploitation and evolved in more competitive socio-ecologies as well.