In one experimental condition, the arena contained only large tokens, and the only way for robots to increase their fitness was to cooperate in pushing them . Accordingly, robots readily evolved the ability to cooperatively push large tokens towards the white wall in all 20 evolutionary replicates that were conducted. However, when the arena contained both large and small tokens, the behaviour of robots was influenced by the group kin structure. In groups of unrelated robots (i.e., robots whose genomes where not more similar within than between groups), robots invariably specialised in pushing the small objects, which was the most efficient strategy to maximise their own individual fitness them (i.e., large tokens provided an equal direct payoff as a small token but were more difficult to successfully push). By contrast, the presence of related robots within groups allowed the evolution of altruism. When groups were formed of “clonal” robots all having the same genome, individuals primarily pushed the large tokens even though it was costly, in terms of individual fitness, for the robots pushing (Video S6).Up next: robots evolve jealousy, petty rage, and scorn.
[via Reed A. Cartwright]