The role of familiarity in signaller–receiver interactions

Abstract

In animal communication, individuals of species exhibiting individual recognition of conspecifics with whom they have repeated interactions, receive signals not only from unfamiliar conspecifics, but also from individuals with whom they have prior experience. Empirical evidence suggests that familiarity with a specific signaller aids receivers in interpreting that signaller's signals, but there has been little theoretical work on this effect. Here, we develop a Bayesian decision-making model and apply it to the well-studied systems of primate ovulation signals. We compare the siring probability of learner males versus non-learner males, based on variation in their assessment of the best time to mate and mate-guard females. We compare males of different dominance ranks, and vary the number of females, and their cycle synchrony. We find strong fitness advantages for learners, which manifest very quickly. Receivers do not have to see the full range of a signaller's signals in order to start gaining familiarity benefits. Reproductive asynchrony and increasing the number of females both enhance learning advantages. We provide theoretical evidence for a strong advantage to specific learning of a signaller's range of signals in signalling systems. Our results have broad implications, not only for understanding communication, but in elucidating additional fitness benefits to group-living, the evolution of individual recognition, and other characteristics of animal behavioural biology.rsif.royalsocietypublishing.org J. R. Soc. Interface 15: 20180568

Combined perceptual and chemical analyses show no compelling evidence for ovulatory cycle shifts in women’s axillary odour

“…Some of the earlier studies showing cyclic shifts in odour attractiveness presented men with multiple samples of the same woman [ 8 , 20 ]. Thus, multiple encounters with different odours of the same woman could help men to better distinguish potential olfactory fertility cues as they gain higher familiarity with her scent [ 26 ]. However, in a more recent study, men were very poor at discriminating the female’s fertile state from odour attractiveness even with multiple odour samples of the same women in direct comparison [ 22 ].…”

“…Furthermore, in most studies, men assessed fertility information of one woman over her cycle, thus simulating repeated encounters with the same woman. While this familiarity can aid in the interpretation of cues [ 26 ], the ability to detect and decode female fertility in a single encounter could enable more immediate male courtship decisions. Single encounters have only been investigated for between-women effects, comparing nearly ovulating and non-ovulating women.…”