There's a new book coming out that I, admittedly, have not read. So I don't know whether my criticisms of this article should be aimed at the author or at The New York Times. Regardless, someone doesn't know jack-shit about chimps.
First off, the author is assuming that our behavior is similar to chimps, while that is hardly an accepted fact. Lots of researchers think that our ancient society was closer to the bonobo.
So what caused us to become primarily monogamous? Well... wait. Since when have we been primarily monogamous? I know lots of sex researchers who would dispute this claim. What about theories that we pair-bond for three years, with a huge burst of sexual desire at the beginning. This gets us pregnant and provides care long enough for the baby to become self-mobile. Where does that fit into his theory? In born behavior like that must have come long before our development of weapons.
Regardless, the article, at least, contends that the force behind monogamy was "perhaps, the invention of weapons — an event that let human ancestors escape the brutal tyranny of the alpha male that dominated ape societies."
What brutal tyranny of alpha males? Apparently, the NY Times didn't bother reading the Wikipedia entry on chimp social structure, where "more than one individual may be dominant enough to dominate other members of lower rank."
Furthermore, "the 'dominant male' does not always have to be the largest or strongest male but rather the most manipulative and political male who can influence the goings on within a group. Male chimpanzees typically attain dominance through cultivating allies who will provide support for that individual in case of future ambitions for power."
There is no tyranny of the alpha male in chimp societies. And to put the explanation exclusively on the males WILDLY ignores the complexities of chimp society. Again, from nothing more than Wikipedia;
"Its often the females who choose the alpha male. For a male chimpanzee to win the alpha status, he must gain acceptance from the females in the community as they are the ones who actually dictate the lifestyle... In some cases, a group of dominant females will oust an alpha male who is not to their preference and rather back up the other male who they see potential of leading the group as a successful alpha male."
This is the reason why there's such blowback on evolutionary psychology. They make inferences and conclusions that are, at best, fleetingly supported by evidence. Broad statements can be made, but to argue that details that this or that variable was definitely the cause of a shift in behavior or evolution is not, NOR EVER WILL BE, supported by evidence. This book is intellectual masturbation.