Personality variation is eroded by simple social behaviours in collective foragers

Abstract

The movement of groups can be heavily influenced by ‘leader’ individuals who differ from the others in some way. A major source of differences between individuals is the repeatability and consistency of their behaviour, commonly considered as their ‘personality’, which can influence both position within a group as well as the tendency to lead. However, links between personality and behaviour may also depend upon the immediate social environment of the individual; individuals who behave consistently in one way when alone may not express the same behaviour socially, when they may be conforming with the behaviour of others. Experimental evidence shows that personality differences can be eroded in social situations, but there is currently a lack of theory to identify the conditions where we would expect personality to be suppressed. Here, we develop a simple individual-based framework considering a small group of individuals with differing tendencies to perform risky behaviours when travelling away from a safe home site towards a foraging site, and compare the group behaviours when the individuals follow differing rules for aggregation behaviour determining how much attention they pay to the actions of their fellow group-members. We find that if individuals pay attention to the other members of the group, the group will tend to remain at the safe site for longer, but then travel faster towards the foraging site. This demonstrates that simple social behaviours can result in the repression of consistent inter-individual differences in behaviour, giving the first theoretical consideration of the social mechanisms behind personality suppression.

Red deerCervus elaphusblink more in larger groups

“…Most animal species spend some part of their lives aggregated together in groups, and many benefits have been proposed and tested for this behavior (Krause & Ruxton, 2002;Ward & Webster, 2016). For prey species, grouping behavior can offer protection from predators through both the dilution of individual risk if an attack occurs (Bednekoff & Lima, 1998;Hamilton, 1971;Pulliam, 1973) and an increase in the chance of successfully detecting an approaching predator due to the combined vigilance effort of the group (Lima, 1990;McNamara & Houston, 1992;Pulliam, 1973), along with other anti-predator advantages of grouping behavior such as synchronizing activity to dilute risk (Carere et al, 2009;Mónus & Barta, 2016;Rands, 2011;Rands et al, 2003;Rands & Ioannou, 2023). If an animal is being actively vigilant, it may be unable to conduct (or less efficient at) other important behaviors (like foraging or resting) at the same time (e.g.…”

Group phenotypic composition drives task performances in ants

“…Previous investigations of the interplay between individual and group behaviour gave conflicting results. Some studies showed that inter-individual differences in behaviour are repressed when individuals interact with other group members, suggesting that personality differences among individuals would not reflect group behaviour [22,23].…”