Data from: Personality composition is more important than group size in determining collective foraging behaviour in the wild

Describing the factors that shape collective behaviour is central to our understanding of animal societies. Countless studies have demonstrated an effect of group size in the emergence of collective behaviours, but comparatively fewer have accounted for the composition/diversity of behavioural phenotypes, which is often conflated with group size. Here we simultaneously examine the effect of personality composition and group size on nest architecture and collective foraging aggressiveness in the social spider Stegodyphus dumicola. We created colonies of two different sizes (10 or 30 individuals) and four compositions of boldness (all bold, all shy, mixed bold and shy, or moderate individuals) in the field and then measured their collective behaviour. Larger colonies produced bigger capture webs and attacked prey with more individuals. Whereas, colonies containing a higher proportion of bold individuals responded to prey more rapidly and with more attackers. In terms of the number of attackers and latency to attack a prey stimulus, group personality composition had an effect size more than five times that of colony size. This suggests that personality composition is a more potent (albeit more cryptic) determinant of collective foraging in these societies.