Why do we have sex? What makes us, at any particular time, choose to engage in sexual activity with another person?
The popular view is that we all have an innate desire for sex, a physical itch which is often overwhelming and which needs to be satisfied on a regular basis. Commonly referred to as libido, it is also called sex drive to suggest a similarity with hunger or thirst, but these are necessary for survival whereas sex isn't.
When consensual sex is portrayed in movies, from PG to super X-rated, it usually begins with an erotic charge between the partners. The action might proceed slowly, teasingly, into a prolonged intermingling of body parts ending in noises of orgasmic delight, or erupt in frantic coupling, often against a convenient wall. The overall impression is of lusty, hot, intense desire and release. Men and women are equally portrayed as creatures of strong sexual passions that can ignite explosive, deeply satisfying sex.
Despite this being fantasy, repeated exposure to these images does shape people's expectations of what libido should be. Sex therapists see many women, more so than men, whose complaint is that they have never, or only sometimes, had that feeling of physical desire for sex that they have heard so much about: they say they "want to want", to feel the pull of spontaneous heat that needs no thought, just reaction. They believe that they are missing out on an experience that should be their birthright, so what is wrong with them?
This raises the vexed question of whether male and female libido are felt and expressed in the same way. The traditional belief was that (good) women rarely -- if ever -- experienced sexual desire, and only had sex as a marital duty and to achieve a pregnancy. Male desire was regarded by some as an animalistic urge over which they had little control if tempted, so women were expected to be the gate-keeper of male sexual passion.
This view was superceded in the 1960s, in reaction to the combined effect of women's quest for gender equality which included equal right to sexual pleasure, the development of effective contraception making sex more about recreation than procreation, and the rapid emergence of mass media with its increasing exposure of sexual information and sexual acts. By 1980, the official psychiatric view was that male and female sex drive was the same, and was characterised by regular fantasies about sexual activities and regular desire for these activities. This desire was 'appetitive', that is, it involved an active searching to satisfy an internal need. Lack of sex drive was therefore a disorder which may require treatment to expose any underlying psychological problem.
This view lasted for quite a while, but by 2000, many of us working in the field were seeing more and more women who complained that this spontaneous, appetitive desire eluded them, despite the fact that they had sex-positive attitudes and were able to enjoy sex once they decided to have it. Instead, their first reaction to their partner's sexual overtures was often "not now, I can't be bothered/I'm tired/busy...", and they rarely thought to initiate sex themselves.
In response, Rosemary Basson, a Canadian gynaecologist, developed what she described as the circular model of sexual desire. This simply means that people have sex for many different reasons, not just physical desire. So, for example, a woman might choose to have sex for emotional reasons such as the need for intimacy, or reassurance, or to please her partner, but then become aroused once sexual activity has begun. This is now termed 'responsive' desire.
Research suggests that about a third of women mostly engage in sex for emotional reasons with no desire present. Probably another third sometimes choose to have sex in the absence of desire, and some women will only have sex if they feel initial desire for it. While some women with no initial desire ultimately arouse and have orgasm, others enjoy the encounter without any sexual response if it meets their emotional needs, and this is now recognised as a normal, healthy form of sexual pleasure.
As a result of this body of research, the concept that every woman should or can have an appetitive sex drive has been abandoned and the more general term, sexual interest, has been adopted, which reflects the woman's willingness to engage in sex for reasons that are meaningful to her.
It makes sense from an evolutionary perspective that there are women with an absent or limited capacity for lusty desire. From earliest history, women have often been required to have sex whether they felt desire not, and were able to become pregnant, thus passing on genes for all levels of libido. By contrast, males with low libido would be less likely to have sex, giving the genetic advantage to males with a stronger desire for sex.
Although there do seem to be some differences between male and female libido, there are many similarities. Recent research has found that some men also often choose to have sex before they feel any desire or arousal, and are seeking emotional connection, with ejaculation and orgasm a secondary consideration. Men can also experience loss of libido for a variety of reasons, including performance pressure, stress, anxiety and depression. Most men, however, have experienced regular sexual desire at some stage in their lives.
While this new understanding of sexual interest is a relief to some women (and their partners), it is disappointing to others who really, really want to experience hot, lusty, overwhelming sexual desire.
Dealing with issues such as stress and relationship problems that may help lift a struggling libido. Ultimately, though, you may need to find your own reasons to say "yes" rather than "no" when sex is offered: What's in it for you to have sex?
This post first appeared on July 18, 2016.