A paper published in Trends in Ecology and Evolution by Damien Farine and co-authors highlights the importance for considering the evolutionary feedback between individuals and the phenotypic composition of their social environment. When phenotypic structure exists in a group, community, or population of animals, then selection can operate across multiple scales. When social or group-level selection arises, it can induce an evolutionary response in individuals, thus driving the emergence of plasticity or social decision-making rules. The paper reports such findings across a range of organisms, proposes a unified framework to study group phenotypic compositions, and makes a number of novel predictions using this framework. Read the paper here.