Could the spread of bacterial sexually transmitted infections such as chlamydia, gonorrhea and syphilis in ancient civilisations be the reason why most of us are so set on finding 'the one'? According to a new study published in The Guardian, the rise in STIs in polygynous societies around 10,000 years ago may have pushed humans towards monogamy.

Scientists at Canada's University of Waterloo used computer models to examine how infertility causing STIs affected different sized populations. They found that in smaller hunter-gatherer populations where multiple sexual partners were the norm, STI outbreaks were short-lived. In contrast, STI endemics in larger polygynous societies had a much more drastic effect, leading to a loss in population. As result, researchers suggested it was the monogamous individuals who gained status in the community by 'punishing' polygynous activity.

The researchers argue that STIs could have led to a kind of socially imposed monogamy in our agricultural communities (i.e. our ancestors).  "A lot of the ways we behave with others, our rules for social interaction, also have origins in some kind of natural environment," said Chris Bauch from the University of Waterloo. While not all experts agree with the study results, it's a fascinating theory. And just think - if condoms were around back then, maybe we'd all be be living in a kind of sister-wife scenario à la TV series Big Love?

Monogamous? STIs from our ancestors might be to blame