Deacon's dilemma: The problem of pair-bonding in human evolution
Humans have an unusual mating system - nominally monogamous pair-bonds set within multimale/multifemale communities. In the context of large, dispersed communities, this inevitably places a significant stress on mating strategies, especially for males for whom paternity uncertainty is a real problem. I discuss the nature of this bonding process in terms of the proximate mechanisms that make it possible, and then ask why such a phenomenon might have evolved. I suggest that the evidence for the importance of biparental care (the conventional explanation) is weak, and a more likely explanation is that females attached themselves to males in order to reduce the risks of harassment and infanticide from other males (the 'hired gun' hypothesis). Finally, I ask when pair-bonds of this kind might have evolved during the course of hominin evolution, and suggest that it might have been quite late. © The British Academy 2010.