Do non-human animals copy successful and prestigious models? Disentangling payoff-biased transmission across taxa

As the empirical literature on social learning across taxa has exploded, some claims that certain social learning strategies [SLSs] are uniquely human have been challenged. While enriching, the interdisciplinary nature of cultural transmission studies has also weakened semantic and conceptual congruence across fields. A theoretical gap has thus been growing between the observed animal behaviors and the hypothesized SLSs underlying them. This review specifically explores the taxonomic distribution of SLSs based on payoff-correlates like a model’s success or prestige, and the possibility these extend beyond humans. Such ‘copy-if-better-model’ (i.e., indirect bias) strategies are functionally distinct from ‘copy-if-better-variant’ (i.e., direct bias) strategies, though they are both often generically described as payoff-biased transmission. Perhaps most importantly, ‘copy-if-better model’ heuristics may increase the risks of maladaptive transmission, and have been implicated in the spread of fitness-reducing behaviors in humans. This paper first proposes broad criteria of cognitive mechanisms that are required for indirectly biased SLSs to be deployed. It then reviews the empirical evidence for these strategies across non-human animals. While several studies call into question the ability of non-human animals to preferentially copy a model in the absence of any immediately and directly observed relative benefits (e.g., payoffs), multiple others meet the criteria for indirectly biased transmission. Observing indirectly biased transmission dynamics across a range of different taxa could be indicative of the adaptive potential of these SLSs (e.g., Boyd & Richerson, 1985). On the other hand, species that rely on this type of SLS may be vulnerable to the transmission of maladaptive information, suggesting future research into how animals mitigate the risks inherent in such a low-cost but potentially uncertain heuristic.