---
title: "Monogamy &#8211; the natural choice?"
date: "2013-07-31T17:17:18+01:00"
modified: "2013-07-31T17:17:18+01:00"
url: "https://rationalists.org.uk/2013/07/31/monogamy-the-natural-choice/"
post_id: 5864
categories: ["Uncategorised"]
---

# Monogamy – the natural choice?

![Gibbons](https://rationalists.org.uk/wp-content/uploads/sites/2/images/gibbon-couple.jpg "Gibbons mate for life (socially that is)")

A number of religious traditions swear by the sacredness of monogamy. The idea of a man and a woman partnering for life to raise a family forms the cornerstone of the beliefs of many, even though descriptions of several different kinds of marriage (including polygamy) can be found in the holy books. To the less traditional observer, monogamy may seem like a priest-enforced social-construct that is only designed to hinder our libidos. But, behind the virginal veils and sparkling diamonds of bridal reality shows, could there be an evolutionary reason for our monogamous aspirations?

Some scientists in Britain certainly seem to think so. Two papers studying monogamy were published on Monday. Dr. Tim Clutton-Brock and Dr. Dieter Lukas from the University of Cambridge [based](http://www.nature.com/news/conflicting-studies-rekindle-monogamy-debate-1.13462) their study on a previously published evolutionary tree of 2,288 species of mammal. Their research [established](http://www.nytimes.com/2013/07/30/science/despite-two-new-studies-on-motives-for-monogamy-the-debate-continues.html?_r=0) a link between solitary females and monogamous pairing: when females become hostile towards each other (e.g. for lack of food) and begin to live in a non-overlapping range meaning that males need to turn monogamous to stay close to the females. Monogamy then develops as a matter of convenience: it is easier for the male to keep rivals away from the female by pairing up for a longer term. Monogamy caused by aggressive solitary females may not be the best material for romantic novels, but the researchers [say that](http://news.nationalpost.com/2013/07/29/two-major-research-projects-reveal-origins-of-human-monogamy-too-bad-their-conclusions-are-contradictory/) “under these conditions, guarding individual females may represent the most efficient breeding strategy for males.”

The second study, headed by Dr. Christopher Opie from the University College London, came up with a different explanation for the evolution of monogamy. In their research of 230 primate species, the researchers [found](http://www.nature.com/news/conflicting-studies-rekindle-monogamy-debate-1.13462) that monogamous practices evolved to protect offspring from rivals. It is not an uncommon occurrence for rival males to kill infants to cause the mother to start ovulating again (mammals are effectively sterile when lactating). To prevent this from happening it is in the interest of the father to stick with the mother, and even participate in the care of the offspring. Dr. Opie [described](http://www.theguardian.com/science/2013/jul/29/mystery-of-monogamy-scientists-report) the study’s findings: “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.” Not exactly Jane Austen either.

Can the theories of hostile females and murderous males be reconciled? Dr. Clutton-Brock [seems](http://news.nationalpost.com/2013/07/29/two-major-research-projects-reveal-origins-of-human-monogamy-too-bad-their-conclusions-are-contradictory/) to think not: “We can find no evidence of any close association between the evolution of monogamy and the risk of male infanticide, which has been suggested as an alternative driving force.” Dr. Opie points out that pairing for life isn’t the only way to protect your offspring. “There are a number of responses to infanticide,” of which “monogamy is not the only one,” he [said](http://news.nationalpost.com/2013/07/29/two-major-research-projects-reveal-origins-of-human-monogamy-too-bad-their-conclusions-are-contradictory/). “For example, female chimpanzees mate with as many males as possible to make sure that all the males think that they’ve got at least some chance of being the father. And that’s a pretty good anti-infanticide strategy, in fact. But some primates use monogamy as the strategy.”

Only [around](http://www.theguardian.com/science/2013/jul/29/mystery-of-monogamy-scientists-report) 3% of mammals are monogamous (and mainly socially so – promiscuity is not unheard of), while 90% of birds pair for long periods. While the number among primates is higher than mammals in general, scientists warn not to draw parallels between the research findings and human behaviour. Dr. Clutton-Brock [argues](http://news.nationalpost.com/2013/07/29/two-major-research-projects-reveal-origins-of-human-monogamy-too-bad-their-conclusions-are-contradictory/) that because of culture’s overwhelming influence “it’s important to be very cautious about what you say about humans.” [His own opinion](http://news.nationalpost.com/2013/07/29/two-major-research-projects-reveal-origins-of-human-monogamy-too-bad-their-conclusions-are-contradictory/)? “I’m far from convinced that humans are really monogamous.” So much for romance.