For what it is I think it's very well done, but it'a little too narrow and too theoretical for my taste. Chapais argues that, given certain social structures, the addition of pair-bonding (with the paternal recognition that goes along with it) allows for a vastly expanded social web. For patrilocal species (such as our close relative, the chimpanzee), to lack pair-bonding and paternal recognition means that basically the only elemental unit of social relation you can have is mother-child. Add in pair-bonding, and everything opens up. This then allows for social bonding across groups, which brings us to the basic prehistoric tribe, a social structure that Chapais argues can be developed even without language. Despite the paucity of evidence, the logic is fairly convincing.