We have moved on from the Edwardian model of marriage, in which many married couples expected to have little or even no sex. Through the 20th century, men’s, and especially women’s, expectations of sex and love, and the relationship between the two, have risen. Today we move in and out of relationships far more easily. We have a lot more sexual experience and we are more willing to leave someone.

Our lifestyle today wasn’t possible for most people before the 1960s and the introduction of the Pill and easy divorce. Couples were often forced to reconcile their differences, and did so not by sharing their desires but by accepting rigid roles. Few of us would want to go back to that.

To understand why people can have different levels of desire, we need to do more than say that they are tired or busy and have gone off sex. What was the sexual experience they have “gone off” like?

Since the 1960s, sex has become more commonplace. But we have inherited a prudish culture in which tenderness and sexual skill are suspect. Not enough has changed since Marie Stopes suggested in 1918 that men needed to learn how to “woo their wives” – that is, foreplay but after a slow seduction. Men are often still clumsy in their approach, and many women are more prudish than they realise; once the initial excitement of a relationship wears off, they lose interest. Neither party tries hard enough to recall and recreate what made sex exciting and romantic.

The 1970s plunged us into a long-hours culture. Women work full time, they have children later. These trends limit the time that couples have together.

We joke about sex but still find it hard to convey our real needs. We have to redress the time balance and encourage talking about our desires, to reach a stage where people don’t feel that they “owe” (or don’t owe) sex.

Dr Cook is an historian of sexuality at the University of Birmingham

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