title: Cultural coevolution of norm adoption and enforcement when punishers are rewarded or non-punishers are punished.
abstract: A number of studies have shown that social norms can be maintained at a high frequency when norm-violators are punished. However, there remains the problem of how norm-adopters and punishers coevolve within a single group. We develop a recursive system to examine the coevolution of norm-adopters and punishers where the viability of punishers is enhanced by one of two "metanorms": (1) Norm-observers reward punishers for punishing norm-violators (Reward Model); (2) Punishers punish non-punishers (Punishment Model). Both models generate a bistable system and each is characterized in phenotype frequency space by a distinct region of attraction to the equilibrium consisting of only norm-adopting punishers. Using a Monte Carlo simulation, we find that cultural drift may allow norm-adopters and punishers to coevolve from invasion into this region of attraction, resulting in their fixation. This coevolution typically occurs across a wider range of conditions under the reward- than the punishment-based metanorm. We also show that, under appropriate conditions, a large negative statistical association between the two traits may evolve only under the Reward Model. Furthermore, for each metanorm, a population of norm-adopters who always observe the norm can be locally stable over a continuum of punishment frequencies.
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA. jeremykendal@gmail.com
authors.forename: Jeremy
authors.initials: J
authors.lastname: Kendal
authors.forename: Marcus W
authors.initials: MW
authors.lastname: Feldman
authors.forename: Kenichi
authors.initials: K
authors.lastname: Aoki
mesh_terms: D003468:Cultural Evolution; D003469:Culture; D006801:Humans; D015233:Models, Statistical; D009010:Monte Carlo Method; D011678:Punishment; D012201:Reward; D012919:Social Behavior