These adaptive changes appear to have strengthened interindividual affiliation, increased male-male tolerance and facilitated the stepwise aggregation from independent one-male, multifemale groups to large multilevel societies, the article said.

文章说，这些适应性变化似乎加强了个体间的联系，增加了男性-男性的容忍度，并促进了从独立的一男多女群体逐步聚集到大型多层次社会。