Two studies of monogamy in mammals and primates recently gained much attention by the media, partly because they contradict the bestseller Sex at Dawn (see list of reports under this article). Accordingly on Facebook and Twitter there were questions about them to Chris Ryan, who together with his wife Cacilda Jethá has written Sex at Dawn, about which I published an essay.
Monogamy developed as a means against male infanticide – or did it?
According to some media reports everything seems clear. Monogamy is widespread and has become established because for the males of a species it was the best way to prevent the killing of their children by any rival or successor in the partnership, says one of the studies.
The other study found that the reason for monogamy rather seems to be that females develop a kind of hostile behavior toward each other and the males have no other option than to choose one of them.
It turns out that the studies come to different results. The heads of these studies, Christopher Opie and Dieter Lukas, criticize each others methods, declaring that the approach of the other study was not adequate.
All this surprised me, since science, notably David Barash, has for years been of the opinion that monogamy in the animal kingdom is practically non-existent. And if you read the reports about the studies more closely, you find that what they actually talk about is social monogamy. That means animals stay together as a couple, but secretly use every opportunity to have sex outside of their current relation including having children with other partners. If that sounds familiar it is because it is also very human to act like that, even if these studies are expressly just about animals and not homo sapiens.
So it’s Sex at Dawn and promiscuity?
One can of course never be so sure, as a lot of what Sex at Dawn is about happened tens of thousands of years ago and even earlier. But i´d like to refer the interested reader to some of Chris Ryan’s tweets in which he expresses doubts about the studies. Ryan points out that none of the studies says anything about bonobos, our closest relatives in evolutionary development. Moreover, infanticide in primates happens especially in harem-based groups, not in groups of the social structure of bonobos (and us).
Promiscuity? At least in Homo sapiens that was once normal and still is
A very good article about these studies can be found in the german weekly newspaper ZEIT, which reports about the two studies thoroughly. There you will also find sobering statements about monogamy and polygamy from Peter Kappeler, Professor of sociobiology and anthropology at the University of Göttingen and Head of the Department of Behavioral Economics and Sociobiology at the German Primate Center.
Kappeler says that Homo sapiens had ancestors that lived promiscuous or polygamous. The reasons for the transition to monogamy have not yet ultimately been determined. And according to Kappeler if you look to Africa there is not a single ethnic group in wich monogamy can be found at all. So Kappeler suggests: “Whoever claims that monogamy had always been the only acceptable form of organization of human beings should visit an anthropology lecture.”
- Abstract of the study headed by Dieter Lukas
- Abstract of the study headed by Christopher Opie
- Article in german NTV: This is how mongamy developed
- Article in german weekly ZEIT: Some simply find being unfaithful way too strenuous
- Article in New York Times: Despite Two New Studies on Motives for Monogamy, the Debate Continues
- Article in Sciencemag: Monogamy May Have Evolved to Prevent Infanticide
@sunnyqdiana Any study that assumes humans are naturally monogamous strikes me as deeply flawed.
— Christopher Ryan (@ChrisRyanPhD) July 29, 2013
.@danielsronan These studies make no sense to me. Infanticide most common in harem-based mating. No mention of bonobos.
— Christopher Ryan (@ChrisRyanPhD) July 30, 2013
Notice: This article is translated and some contents might have been added or left out to better meet the needs of an international audience from an original article on one of my german websites Viktor-Leberecht.de or Polygamie-ist-gut-fuer-sie.de (engl:Polygamy is good for you). How i do my translations. Last updated: August 3, 2013 at 10:32 am © Viktor Leberecht All rights reserved. Please feel free to share my content on Social-Sharing-Services. What do you think? Leave a comment here. For your convenience you may either use the integrated comment system of wordpress in the first comment field, or if you prefer you may post with your Google+ account in the second comment field. You may also send me a question through the contact form or the FAQ.