Behavioral Syndromes in Social Insects

Abstract

Behavioral syndromes -- the consistent covariation of behavioral traits across contexts and individuals, producing repeatable behavioral types or personalities -- have been widely documented in solitary animals but their expression in social insects, where individual behavior is embedded within the collective behavior of a superorganism colony, represents a fundamentally different and less well-understood level of organisation. This study presents the most comprehensive comparative analysis of behavioral syndromes in social insects yet conducted, quantifying individual and colony-level behavioral repeatability across 247 colonies from 18 species spanning ants, bees, wasps, and termites, using a standardised multi-context behavioral assay battery repeated across four seasonal time points per colony. Individual-level behavioral syndromes were confirmed in 14 of 18 species (78%): individuals consistently classified as bold-active or cautious-inactive across foraging, nest defence, and exploration contexts (mean repeatability r = 0.47 + 0.14). Colony-level syndromes were confirmed in all 18 species (100%; r = 0.64 +- 0.12). Colony syndrome predicted colony performance: bold colonies showed 34.7% higher food acquisition but 18.4% higher worker mortality under predator exposure, confirming a boldness-risk trade-off at the colony level. Queen genotype explained 28.4% of colony syndrome variance, confirming a heritable genetic component to colony behavioral type.