YouGov has surveyed attitudes on polygamy, to see if there is a direction of travel for further 'liberalisation' in the definition of marriage. (I put 'liberalisation' in quotation marks because the word has a positive suggestion of freedom. It's like using the word 'decay' to describe change, it's not a neutral term).
39% of Brits think humans are not monogamous by nature, but at the same time only 18% think that polygamy is morally acceptable. Even though only 42% (!) think we're naturally monogamous, nearly 3/4 think that monogamous relationships can be successful if people work at it hard enough.
So for some of us at least, we don't think the law around marriage, sexuality and relationships should be based on what comes naturally to us. I'd have liked to see a follow up question to those who thought having multiple partners was natural but immoral: why? Or to the 47% who believe that, even if everyone involved gives their consent, having multiple relationships at the same time is wrong. Why?
YouGov, from what I can see, hasn't started tracking these results over time, so there's no way of telling if attitudes are changing, and by how much. Much of our education and culture around sex is based on informed consent: if you want to do it, and they want to do it, then what's the problem. There's also a presumption of freedom: do what you want to do, as long as it doesn't hurt anyone.
There's a sizeable chunk of Brits (I'm one) which doesn't believe that 'natural' is a reliable guide to 'moral' or 'legal'. If it was, we wouldn't need so many laws: but many of us find it 'natural' to hit people, cheat, speed, steal, fiddle taxes, lie, be greedy etc. Deferred gratification is one of the key skills learned early in life, to learn to say 'no' to what we want RIGHT NOW. Self control, in other words. The idea of self control when it comes to sex has become counter-cultural in the space of 3 generations. We've also been very nervous about promoting monogamy and its benefits (look at the recent fight around the token recognition of marriage in the tax system) because that's seen as stigmatising lone parents or being nanny state about people's sexual choices.
We may one day arrive at the right balance of nature and choice on one hand, and morality and self-control on the other. But leaving it all to the individual to make their own mistakes and find their own way is cruel. We're surrounded by the wreckage. There is an accumulated wisdom about marriage and relationships from many generations, and from Christian teaching, but we've been too nervous in talking about it because we don't want to be seen as lecturing people about sex and their own personal choices.
Christian teaching about sin is clear: doing what comes naturally isn't the same as doing what is good. Judging by the survey results, a lot of people get that, but talking about 'sin' will get us nowhere in a post-Christian society. How do we talk about God's gift of sex in a way that holds on to the wisdom, but still gets heard?