Competitive advantage of rare behaviors induces adaptive diversity rather than social conformity in skill learning

Recent studies have emphasized the role of social learning and cultural
transmission in promoting conformity and uniformity in animal groups, but
little attention has been given to the role of negative
frequency-dependent learning in impeding conformity and promoting
diversity instead. Here we show experimentally that under competitive
conditions, that are common in nature, social foragers (although capable
of social learning) are likely to develop diversity in foraging
specialization rather than uniformity. Naïve house sparrows that were
introduced into groups of foraging specialists did not conform to the
behaviour of the specialists but, rather, learned to use the alternative
food-related cues, thus forming groups of complementary specialists. We
further show that individuals in such groups may forage more effectively
in diverse environments. Our results suggest that when the benefit from
socially acquired skills diminishes through competition in a negative
frequency-dependent manner, animal societies will become behaviourally
diverse rather than uniform.