Systems leadership: how chief executives manage tension between organisation and system pressures.

Aim: System leadership is the requirement for a leader of a single organisation to operate on behalf of a wider system, rather than their individual organisation. The current policy landscape does not incentivise system leadership, as many national structures emphasise a focus on individual organisations. This study aims to understand how chief executives in the National Health Service (NHS) in England implement system leadership in practice when faced with decisions that benefit the system to the detriment of their own trust.

Kinship underlies costly cooperation in Mosuo villages.

The relative importance of social evolution theories such as kin selection, direct reciprocity and need-based transfers in explaining real-world cooperation is the source of much debate. Previous field studies of cooperation in human communities have revealed variability in the extent to which each of these theories explains human sociality in different contexts. We conducted multivariate social network analyses predicting costly cooperation-labouring on another household's farm-in 128 082 dyads of Mosuo farming households in southwest China.

The narrow gap between norms and cooperative behaviour in a reindeer herding community.

Cooperation evolves on social networks and is shaped, in part, by norms: beliefs and expectations about the behaviour of others or of oneself. Networks of cooperative social partners and associated norms are vital for pastoralists, such as Saami reindeer herders in northern Norway. However, little is known quantitatively about how norms structure pastoralists' social networks or shape cooperation.