The romantic couple, whether heterosexual or same sex, is at the centre of the universe. Not only is being part of a couple seen as the norm; but those either willingly or unwillingly single can be made to feel like failures and outcasts.

But things are slowly changing, according to recently published research focusing on “the couple norm”.

Led by Sasha Roseneil, a professor at University College London (UCL), the research entitled The Tenacity of the Couple-Norm draws on data from the UK, Bulgaria, Portugal and Norway. It shows that in recent years there have been significant changes in what Roseneil calls “intimate citizenship”, which includes laws and policies relating to coupledom and the way people live their private lives.

But is living as half of a couple still the ideal for most people? Roseneil’s research found that yes, it is still seen as the most fulfilling way to live but less so than a decade ago. More couples live apart, fewer are marrying, and non-monogamy is jostling for equal attention with traditional exclusivity. But why does the monogamous twosome remain at the centre of the universe for most?

Being single has always been stigmatising for women in particular. While “bachelor” has a rather glamorous connotation, “spinster” – a word only made obsolete in 2005 – means an unmarried woman who is “no longer young and seems unlikely ever to marry”. In a number of languages, the word translates as an “old maid”. The term “on the shelf” is applied to unmarried women, not men.

What if women who never marry nor have children are happier than those that do? On the publication of his book in 2019, Happy Ever After: Escaping the Myth of the Perfect Life, professor Paul Dolan received countless emails from women of all ages thanking him for speaking their truth.

Nevertheless, figures from the Office of National Statistics (ONS) show that being married or civil partnered remained the most common marital status in 2019, accounting for just over half of the adult population in England and Wales.

Marriage is an outmoded institution built on patriarchal inequality that has no place in modern society

That said, things have been changing. In 2009 figures showed that fewer British people were getting married and that those who did were leaving it until later in life. Meanwhile, half of all marriages were ending in divorce. In 2019 the total number of divorces in England and Wales saw its largest increase in almost 50 years. That same year there were 107,599 divorces of opposite-sex couples in England and Wales: an increase of almost a fifth from the year before.

Thanks to feminism, important new legislation on divorce was passed in the 1920s and 1930s. Consequently, it became increasingly important for politicians and legislators to uphold the institution of marriage. When the Divorce Reform Act was passed in 1969, it became much easier to get a divorce in England and Wales. As such, the 1970s saw an increase in divorce and a decline in marriage generally.

Law, policy and culture push people towards being couples and promote the idea that being paired off is the natural way to live. Marriage is typically viewed as providing couples with a sense of safety and security; yet in 2017 ONS figures showed that unmarried cohabiting couples were the fastest-growing family type in the UK.

While heterosexuals increasingly look for new ways to be together, lesbians and gay men are rushing to the registry office. But the rate of divorce among lesbians is increasing. There were 822 divorces among same-sex couples in 2019, almost twice as many as in 2018; of these, 72 per cent were between female couples.

Being single for a good chunk of adult life has become more common, while marriage has become less so. As Roseneil observes: “It is no longer legally or culturally obligatory for women or men to marry or to stay married, to be or to act heterosexual.”

I am very clear that marriage is an outmoded institution built on patriarchal inequality that has no place in modern society. I have been criticised by some gay men and lesbians for arguing that aping heterosexual convention and choosing marriage is a way of asking to be tolerated, as opposed to seeking liberation from legal coupledom. This is not to do with being against equality, because no part of marriage is about equality. Instead, marriage is about perpetuating privilege.

Things are going in a similar direction in the US. Americans are getting married later in life and more young adults are opting to share a home rather than a marriage licence with their partner. Despite this, what hasn’t altered is the belief that a monogamous relationship is what we are all striving for.

New family structures are beginning to emerge thanks to lockdown

The widely held assumption is that couples are better off than single people. But the coronavirus lockdowns have meant that some couples have been kept apart while others have been thrown together for extended periods. Imagine being in a relationship in which you are bored and/or unhappy and having to spend 24 hours a day together in a tiny dwelling? Unconventional “support bubbles” have been formed between singletons, couples and across generations and, from this, new ways of structuring families are emerging.

Living outside of a traditional couple can be difficult but many more people are braving it. Increasing numbers are choosing to define a close friendship as their primary relationship, with some considering forming a civil partnership with a friend in order to secure the same benefits as traditional couples.

For example, one heterosexual woman interviewed for the UCL research had set up home with her gay best friend and jokingly referred to him as her husband. Theirs is not a romantic or sexual relationship, but they are in a different type of couple. I have heard of other such similar arrangements in the UK.

What about the future? How well will the traditional couple fare? Perhaps as same-sex relationships become more conventional the more adventurous heterosexuals, bored with being boxed in, will become the new sexual outlaws as they tire of domesticity.