We studied several groups of primates and found that group size and neocortex ratio were correlated with network efficiency. Centralisation (whether several individuals are central in the group) and modularity (how a group is clustered) had opposing effects on network efficiency, showing that tolerant species have more efficient networks. Such network properties affecting individual fitness could be shaped by natural selection affecting bot information and disease transmission. The main question of interest is how social network properties and individual attributes within this network effect separately and at the same time the diffusion of transmission (tested through opening of a fruit box as a proxy for information and social learning) and of disease (tested through pseudoectoparasites). Two parallel diffusion experiments, tracking the two different flows at the same time through the same individuals, will be carried out on Japanese macaques at the Koshima field site of Kyoto University, Japan. Ultimately, through an innovative experimental approach, this study aims at understanding the relative influence of different factors inherent in social-living, both cultural (innovation) and ecological (infectious disease), on human sociality.