Human Exceptionalism

Life and dignity with Wesley J. Smith.

Monogamy “Evolved” to Prevent Infanticide?


Evolutionists sure are inventive, always trying to explain everything as caused by natural selection. Now, an anthropological study claims that monogamy “evolved” to prevent infanticide. From the Guardian story.

Scientists in Britain have taken the puzzle of monogamy and boiled it down to one big question: how did it come about in the first place? A new study claims finally to have an answer. 

And what, pray tell, is that?

Next, they [the study's authors] used simulated evolution from 75m years ago to modern day. As the simulation ran, it showed how monogamy rose and fell for different species. Having run the program millions of times, they found that the evolution of monogamy in primates was preceded by one thing only: infanticide by males. “You do not get monogamy unless you already have infanticide, and you do not get a switch to paternal care if you don’t already have monogamy,” said Opie, in research published in the journal Proceedings of the National Academy of Sciences

Opie says the findings are linked to increases in brain size. In primates, brain size expanded as social groups grew larger, which meant that mothers were infertile for longer and more males were close by. For males, infanticide was a strategy to make females fertile again.

Just what we need: Another rationale for Peter Singer to promote infanticide.

But let’s get real.  Monogamy did not “evolve.” It exists because of human exceptionalism.  

Here’s what I mean: Geese don’t “choose” to mate for life and felines don’t “cat around” because they are immoral. They have no choice in the matter. Their mating methods are instinctual.

In contrast, human societies have differed widely over views on sex and commitment to monogamy, with more ancient societies and some current cultures permitting polyamory. That’s because human cultural norms are not biologically determined, as in animal behavior.

Rather, humans have free will. We create, socialize, and enforce moral and ethical codes. In this sense, we are not slaves to impersonal evolutionary forces in our romantic lives. Indeed, the breathtaking refashioning of Western sexual morality just during my lifetime is a vivid example. 

Still, to be fair, there is a place for monogamy in evolution: If I wasn’t monogamous, my wife would kill me. That’s known as the evolutionary drive to survive!


Subscribe to National Review