A new study of paper wasps suggests social interactions may make animals smarter. The research offers behavioral evidence of an evolutionary link between the ability to recognize individuals and social cooperation. Furthermore, genomic sequencing revealed that populations of wasps that recognized each other -- and cooperated more -- showed recent adaptations (positive selection) in areas of the brain associated with cognitive abilities such as learning, memory and vision.

The study focused on two distinct populations of paper wasps (Polistes fuscatus): A southern one from Louisiana where individuals are more uniform in appearance, and a northern one in Ithaca, where individuals have diverse color patterns on their faces. A series of experiments indicated that unlike southern counterparts, the northern population both recognized individuals and cooperated socially with some members over others. The evidence for strong recent positive selection on cognition, learning and memory is much stronger in the northern populations compared to the southern populations.

Though more study is needed, there's some indication that wasps from the northern population have more stable nesting groups, whereas the southern wasps had high turnover of members when they occasionally made nests. The study suggests that being able to recognize individuals makes northern wasps more selective and better able to manage their social profiles, whereas the more homogenous-looking southern wasps interact more indiscriminately and have less consistent, cohesive social interactions.