Helen Croydon: Monogamy is not our natural state

Choosing our family members, wasn't, you would have thought, a matter for the high courts, not in a democratised world anyway. But it seems judicial teams in the most unlikely of places are taking on these new roles, attempting to define our marital nirvana. Last week, a Californian judge ruled that the state's ban on gay marriages was unconstitutional, leaving thousands of people free at last to choose who they marry.

In the same week, Canada resumed its stab at modernising family values. The supreme court in British Columbia – a province unlike California in every possible way – has been asked to review its centuries-old law which forbids polygamy. It has called on the research of sociologists and evolutionists in an attempt to rule whether the monogamous family unit really is the route to Utopia.

The review is way overdue. The law was originally enacted to quash polygamous Mormon sects but now, in our supposedly liberated and religiously tolerant world, it is surely inappropriate for the law to dictate how we chose to spread our amorous affection.

If either lifestyle should be forced on us, it should be polygamy. That is a far more natural human state than monogamy. Unless two people plan to have children together, I cannot see any reason why they should repress natural urges, banish fantasy and force-feed their conscious minds on a mantra of "avert gaze to floor" just so they can live out an oath of devotion.

We Homo sapiens believe we are further along the evolutionary scale than we really are. We have not evolved with the same level of romantic Zen as swans. They really are happy to pluck each other forever more without having a quack at a tempting young chick. But we are romantically more evolved than dogs, who seek nothing more that sexual relief and don't care if they ever see their mate again. We are somewhere in the middle. Long-term love suits us well but life-long does not.

To reject monogamy is not to say promiscuity is rewarding, nor that it is an alternative. Personally, I find the thought of sex with someone with whom I have no mental rapport quite repulsive. I was never allured by casual sex even in those hormonally ravaged university days when everyone and their dog was doing it (not together we hope). But neither do I see the reward in cocooning my world with one other person – one which collapses unless all weekend activities, circles of friends, sexual moods and meal times occur in harmony.

I've always considered life to be far less complicated if we go about it with a series of decent and respectful lovers. Too often emotional connectivity gets hijacked by sexual exclusivity. And what a ruthless hostage taker it is, with all its endless ransom demands for DIY chores, meeting in-laws or pooling bank accounts.

Canada isn't the only country questioning whether monogamy is an outdated ideal. France's first lady, Carla Bruni, famously declared she is "easily bored by monogamy". Last month, Cameron Diaz proclaimed relationships can last "two, five or 20 years" but she doesn't believe in sharing her bed with the same person her whole life.

And this summer a new book, Sex At Dawn, created something of a pop-anthropology craze. The co-authors Christopher Ryan and Cacilda Jetha – a husband and wife duo – argue that the human organism is designed to seek sexual variety and cite adultery amongst our ancestors across all cultures and eras.

This has all come across very anti-monogamist hasn't it? Let me give a levelling comment. Sexual exclusivity is a magical, beautiful bond and one to which I aspire. But only if the motive is genuine passion or, in the case of raising children, there is a legitimate cause for sacrifice. A stable and loving duo of parents with clearly defined roles remain the most credited way to provide a supportive home for a child. Monogamy can certainly help achieve that. But when monogamous lifestyles are driven by convention alone or an aged vow that no longer has any bearing on our lifestyle, it becomes a dull force incompatible with our core nature.