Speaker
Description
Bonds, good and differentiated relationships, among group members have fitness benefits, also bonds among non-kin males and females. Here we explore from a deductive framework in what circumstances Between Sex Bonds (BSB) can be expected in multi-male multi-female primate group. BSB are considered a way to access sources of power that are subject to leverage provided by the other sex. This differs from, yet complements, power obtained through force. We predict that leverage will be higher, 1) when the receiver benefits on average more than the provider, 2) receivers cannot share the resource, and/or 3) the resource is rare and valuable. We expect BSB to be found, 4) when long-term targeting of the same partner yields benefits. We argue that females’ main source of leverage is fertilizable eggs, whereas males mainly have leverage over protection of females and offspring. Systematic testing of these proposals is not yet possible due to a drawer effect, yet found patterns conform to our predictions. The investment in shared offspring may result in interdependency between male and female strategies, but the different services provided by females and males indicate that affiliative exchanges associated with bonds between the sexes will be typically asymmetric and variable over time. Thus, bonds between the sexes are expected in a limited number of circumstances that provide both females and males leverage over sex-specific resources.
