The frame: the film “one Million years BC”
Canadian researchers from the University of Waterloo using computer modeling found that human monogamy was invented by prehistoric people as a way of combating sexually transmitted infections (STIs). A study published in the journal Nature Communications.
According to scientists, once hunter-gatherers began to gather in large groups, becoming settled farmers, there was a risk of spreading STIs. The last possible reason why sexual behavior of the ancient people there was a shift in favor of social norms faithful to one partner.
In their work, biologists have applied methods of computer modeling in order to understand how the demographics of the epidemic and influence the emergence and development of different social attitudes related to sexual life.
The researchers found that if men have multiple sexual partners, in the conditions when the population size becomes sufficiently large (over 300 people), sexually transmitted diseases begin to lower the birth rate. Therefore, the control over mating is more beneficial for individuals and for the group as a whole.
In groups of hunter-gatherers was fairly common that some males could mate with multiple women to increase the number of their offspring. Group size rarely exceeded 30 people, so outbreaks of STIs were weak and had no appreciable impact on the population. However, with the advent of agriculture and the growth of the size of groups polygamy led to serious spread of diseases such as syphilis, chlamydia and gonorrhea. In the absence of medicine that contributed to the high level of infertility.
The researchers emphasize that in such conditions it is logical to establish monogamous rules and punish those who they should not. Therefore, the group enforced monogamy could displace other groups that do not follow these rules.
