Social recognition in the domestic chicken (Gallus gallus): the effect of familiarity and shared valenced experiences

Social animals, humans included, live in a complicated and dynamic social world, in which individual recognition, described as the capacity to identify idiosyncratic features of single individuals, is a key evolutionary ability used to disentangle intricate social relationships. In humans and animals, identification of primary caregivers, siblings and then in-group members is necessary for obtaining social support benefits and establishing long lasting relationships. Filial imprinting helps individuals to build special social bonds and typically is directed towards the mother, and when this is not present it can extend to several other social stimuli. In our study we made use of an optimal social animal model, the domestic chicken (Gallus gallus), with the aim of investigating its ability to individually recognise different familiar and unfamiliar conspecifics. More specially, through a familiarisation phase, we manipulated the valence of shared social experiences (positive and neutral) between companions and then we tested its effect on their ability to individually recognise among familiar conspecifics as well as familiar from unfamiliar ones. Results showed an overall effect of shared valenced experience and a significant social preference for ‘positive’ familiar over ‘neutral’ ones. Study implications and limitations are then discussed.