METRO.CO.UK - May 28 - For a society where monogamy is the most common type of relationship, having more than one partner may seem 'wrong' but Janet Hardy, author of The Ethical Slut, argues that having one sexual partner is not necessarily natural. 'I don't think humans are biologically inclined toward monogamy,' she said. 'No other primate is monogamous and monogamy is very rare in nature. Only 17% of human cultures are strictly monogamous,' Bernard Chapais, of the University of Montreal, wrote in Evolutionary Anthropology. A study in 2016 showed that one in five people in the US reported being involved in consensual non-monogamy at some point in their lifetime. ~20 - 25% of men admit cheating on their wives and 10-15% of women admit cheating on their husbands. ~40% of marriages in England and Wales end in divorce. Is it because we don't want to admit that 'the one' is actually 'the few'? For some, polyamory means a stable relationship, just with an extra person. Technology and science is allowing us to move beyond the idea of a two-parent family. The first three-parent babies have been born, where DNA from three people is mixed. It's only being used to prevent inherited diseases now.