Scientists believe that monogamy was caused by the spread of sexually transmitted diseases.

Published on April 13, 2016

Scientists believe that monogamy was caused by the spread of sexually transmitted diseases.


    Mathematicians from the University of Waterloo (Canada) in their new scientific work explained the causes of monogamy in early human communities. They believe that this change in social behavior was caused by the spread of sexually transmitted diseases (STDs).

    Polygamous relations should have made sense for the ancients, as they increased the chances of the dominant men for the wide distribution of their genetic material and the increase in population. But, according to mathematical models, when communities of a population of 300 people and more are reached, the general distribution of STDs begins to backfire — the number of people falls.

    “Our social norms did not arise in isolation from the environment,” explains mathematician Chris Bach [Chris Bauch]. - On the contrary, we will not be able to fully understand social norms without understanding their roots, originating in the environment. These rules were created under its influence. And now we see how the environment, in turn, changes its shape under the influence of our society. ”

    The simulation tracked a 30,000-year period of community life. It turned out that when the number of hunter-gatherer groups exceeds 30 people, the dynamics of its development changes. Because of the spread of STDs, which, in particular, can lead to infertility, it becomes advantageous for the group to impose monogamous behavior and punish those who do not obey it.

    “In the absence of modern goods such as antibiotics, latex condoms and tracking of contacts of the diseased, bacterial STDs (syphilis, chlamydia, gonorrhea) lead to a very high number of cases of infertility, which strongly affects the demography of the population,” the authors explain in their work.

    So far this is just a mathematical model, and more specific evidence is required to confirm the hypothesis. But it offers the potential for a logical explanation of the causes of monogamy.

    Does this mean that the decline of the institution of the family at least partially to blame the above modern benefits? It would be nice, mathematicians have worked on this issue.