Keywords: Social network Cohesion

Time allocation Population structure In social animals, fission is a common mode of group proliferation and dispersion and may be affected by genetic or other social factors. Sociality implies preserving relationships between group members. An increase in group size and/or in competition for food within the group can result in decrease certain 008; rsible para-years; Van behavior for the maintenance of close social bonds (Schino, 2001). Contents lists available at ScienceDirect journal homepage: www.e Journal of Theor Journal of Theoretical Biology 273 (2011) 156–166reciprocates with the same tolerance and support (Henzi andcsueur@princeton.edu (C. Sueur).Previous studies have shown that when an individual regularly grooms a particular partner, it seems to be more tolerant with thi