Conformity does not perpetuate suboptimal traditions in a wild population of songbirds

Abstract

Social learning is important to the life history of many animals, helping individuals to acquire new adaptive behavior. However despite long-running debate, it remains an open question whether a reliance on social learning can also lead to mismatched or maladaptive behavior. In a previous study, we experimentally induced traditions for opening a bidirectional door puzzle box in replicate subpopulations of the great tit Parus major. Individuals were conformist social learners, resulting in stable cultural behaviors. Here, we vary the rewards gained by these techniques to ask to what extent established behaviors are flexible to changing conditions. When subpopulations with established foraging traditions for one technique were subjected to a reduced foraging payoff, 49% of birds switched their behavior to a higher-payoff foraging technique after only 14 days, with younger individuals showing a faster rate of change. We elucidated the decisionmaking process for each individual, using a mechanistic learning model to demonstrate that, perhaps surprisingly, this populationlevel change was achieved without significant asocial exploration and without any evidence for payoff-biased copying. Rather, by combining conformist social learning with payoff-sensitive individual reinforcement (updating of experience), individuals and populations could both acquire adaptive behavior and track environmental change.social learning | animal culture | conformity | Parus major S ocial learning, the acquisition of behavior by observation of, or interaction with, other individuals, is common to many animal species. It provides a relatively cheap way of acquiring valuable information and shields naive individuals from the risks of engaging in trial and error learning. A range of studies have further highlighted the crucial role of social learning in promoting cultural behavior and shared traditions (1-4) and suggested that the cultural inheritance of information across generations may be an important component of the behavioral ecology of some animals (1, 5, 6). However, social learning may also be disadvantageous, if copied information is outdated or mismatched to the observing individual. How individuals balance costs and benefits of social learning has therefore been the focus of much recent research aiming to understand how natural selection has shaped learning (7).The use of social learning "strategies" is one possible route by which animals can combine and filter different kinds of information to optimize learning outcomes (8-10). Here, individuals use social cues, often from multiple conspecifics, to bias learning in favor of better quality information. These include preferences to copy kin or more prestigious or older individuals, as well as conformist and payoff-biased social learning (11,12). Such learning strategies also have implications for the spread and persistence of information in populations and for cultural evolution more broadly (13,14). For example, conformist transmission, here defined as the disproportionate tendenc...

Changes in cognitive flexibility and hypothesis search across human life history from childhood to adolescence to adulthood

“…However, innovations that are effortful and rare when they first appear within a generation can become effortlessly and widely adopted by the next generation. In fact, among nonhuman animals, cultural innovations are often first produced, adopted, and spread by juveniles (55)(56)(57)(58).…”

The extension of biology through culture

“…A striking case is the high-fidelity spread of alternative foraging behaviors experimentally seeded in substantial communities of great tits (40). Here, Aplin et al (41) show that these behaviors will evolve adaptively as payoffs change, and the authors present evidence that this occurs through an intriguing combination of conformist social learning and payoffsensitive individual learning.…”

“…Hundreds of laboratory experimental studies have demonstrated social learning and transmission in a wide variety of animals. Social learning is now extensively documented in mammals (29), with a particular intensity of research studies in primates (30)(31)(32)(33) and cetaceans (34)(35)(36)(37), in birds (38)(39)(40)(41), in fish (42), and in insects (43,44). The fact that social learning has been shown to play important roles spanning multiple functional contexts (25)(26)(27)(28) suggests that many animals are not simply acquiring one or a few behavioral patterns socially, but rather that social learning is central to their acquisition of adaptive behavior.…”

“…Initial explorations of Darwinian dynamics in the case of animal culture (53) have taken the list of eight key properties extracted from the Origin of Species (9) for testing with human data [the six listed above, plus changes of function and convergent evolution (83)] and through examining studies of animal culture, concluded there is evidence for all of them (although minimal and slow-developing compared with the most recent, cumulative cultures of humans). However, there is evidence that animal traditions with suboptimal payoffs are sometimes, although seemingly not always (85), vulnerable to decay (41), implying the working of the core Darwinian triad, and it seems likely that those animals for which there is now evidence of multiple-tradition cultures are the descendants of lines of ancestors among whom these traditions were progressively added, surviving through their success, as in the case of over 4,300-y-old nut-cracking in chimpanzees, mentioned earlier (46). Nonetheless, experimental studies, for example, of matechoice copying, show that animal social transmission can be evolutionarily consequential, even if short lived (86).…”

Evolutionary Origins of Morality: Insights From Non-human Primates

“…Conformity can be conceptualized in different ways (Van Leeuwen et al, 2015;Whiten and van de Waal, 2016a), from copying the majority, to copying a new behavioral variant while abandoning a personal preference for a previously acquired behavioral variant, to not only copying the majority but doing so with a disproportionate probability. Empirical evidence for such a disproportionate tendency is scarce in humans (Acerbi et al, 2016) and also among animals (Aplin et al, 2017). However, there is increasing evidence in primates for the other forms of conformity.…”