Socio-economic inequalities in smoking and drinking in adolescence: Assessment of social network dynamics.

Aims: We investigated whether (1) adolescents selected friends with a similar socio-economic status (SES), (2) smoking and alcohol consumption spread in networks and (3) the exclusion of non-smokers or non-drinkers differed between SES groups.

Design: This was a longitudinal study using stochastic actor-oriented models to analyze complete social network data over three waves.

Setting: Eight Hungarian secondary schools with socio-economically diverse classes took part.

Reputation and socio-ecology in humans.

Reputation is a fundamental feature of human sociality as it sustains cooperative relationships among unrelated individuals. Research from various disciplines provides insights on how individuals form impressions of others, condition their behaviours based on the reputation of their interacting partners and spread or learn such reputations. However, past research has often neglected the socio-ecological conditions that can shape reputation systems and their effect on cooperation.