We propose a structure to represent the social fabric of a group. We call it the `cohesion network' of the group. It can be seen as a graph whose vertices are strict subgroups and whose edges indicate a prescribed `pro-social behaviour' from one subgroup towards another. In social psychology, pro-social behaviours are building blocks of full-blown cooperation, which we assimilate here with `group cohesiveness'. We then define a formal framework to study cohesive group agency. To do so, we simply instantiate pro-social behaviour with the more specific relation of `successful assistance' between acting entities in a group. The relations of assistance within a group at the moment of agency constitute the social fabric of the cohesive group agency. We build our logical theory upon the logic of agency "bringing-it-about". We obtain a family of logics of cohesive group agency, one for every class of cohesion networks.

If you knew a catastrophic event were set to wipe out society as we know it, how would you act in the days leading up to the'end of the world'? It's a question that many have considered as apocalyptic narratives cling to popularity – and, researchers say players' behaviour in a video game could tell us what to expect. A new study analyzed people's actions in an'end times' scenario, using a closed beta test of the game ArcheAge as a proxy. While some turned to murder and other anti-social behaviours, the study found most people become more social in the face of impending disaster, creating new relationships even as they abandoned plans for the future. If you knew a catastrophic event were set to wipe out society as we know it, how would you act in the days leading up to the'end of the world'?