Social information use may lead to maladaptive decisions: a game theoretic model

Because animals rely on the actions of others to make behavioral decisions in various contexts and social information use has important evolutionary implications, numerous theoretical studies have addressed the question of when it should occur. Despite several predictions of these models are supported by experimental findings, they have focused mainly on animals that can copy others’ decisions, without paying a cost. Yet, the acquisition or exploitation of social information is likely to be costly in many cases, notably when animals compete for depleting resources: social learners then cannot directly copy the decision of others but instead acquire generalized preferences through observation and hence suffer a risk of being unable to use the information previously collected. To explore the conditions that should favor this form of copying (i.e., acquisition of generalized preferences), we developed a mate-choice model with 2 strategies: selective females assess potential partners until they have found an acceptable mate, whereas copier females observe their mating decisions and then search for a male similar in appearance to the accepted mates. Our results indicate that the extent to which animals should rely on personal information logically increases with the costs entailed by social information use, and the proportion of asocial learners can even reach fixation. Furthermore, as the costs of using both personal and social information are frequency dependent on the proportion of social and asocial learners, there are conditions where both strategies coexist within the population, although social information use may lead to maladaptive decisions.