Why did I shag that guy – I mean girl?

In a result that will surprise precisely no-one, researchers at the University of Bristol have concluded that the demon drink makes us less selective when we choose sexual partners.

Participants in this study were either given alcohol, or some sort of disappointing non-alcoholic placebo, and asked to rate twenty male faces, twenty female ones and twenty landscapes. Those who'd had the booze rated both the faces and the landscapes more positively than those who hadn’t — although it seems entirely possible to me that realising you’re drinking imitation beer while everyone else is quaffing ale may make you less charitable towards your fellow man, woman – or indeed scenic vista.
A drink or three may give us rose-tinted glasses – but no amount of alcohol can turn someone we find unattractive into a dead ringer for Ryan Gosling or Kate Upton. Nope, what alcohol does do is lower our inhibitions, and make us more likely to engage in risky behaviour. This means we may be willing to have sex with someone we’d have overlooked with the supercilious disdain of Lady Mary Crawley being propositioned by an unwashed peasant. More seriously, we’re less likely to use condoms as well.
You may be tempted to write this off as boffins wasting time and money to prove the bleeding obvious, and there is some element of truth in that, but scientific research can upset some of our cherished notions – such as the idea that men enjoy sex more than women, or that those with two X chromosomes are naturally better at childcare than those with one. Neither of those statements are true, despite what you’ve been led to believe, so studying the effects of alcohol on sexual selection isn’t without merit — even if the fact that alcohol makes us take risks with our sexual health is something we already know.
In fact, one of the most exasperating things about social science is that the findings are often so damn contradictory. The Bristol University study suggests that alcohol makes us act in rash ways; but another study from Durham University found the exact opposite — that alcohol inhibits the part of the brain that causes impulsive behaviour. It can’t be both — so either one study is flawed, or both are, or something weird is going on.
Many studies of human mating behaviour bypass the question of alcohol in its entirety when examining short-term sexual flings. Over the years I’ve read that women are more likely to choose a good-looking man over an average one for a one-night stand (newsflash!) because subconsciously she is trying to access his superior genetic material; or that a woman in search of a short-term sex partner is actually looking for validation of her attractiveness — her partner’s looks being irrelevant to the enterprise. Some studies have concluded that one-night stands allow women to freely explore their erotic desires, and thus can be more sexually satisfying than a relationship; others have found that, for most women, a hook-up with a randomer is likely to be a bust, orgasmically speaking and therefore — surprise, surprise — less sexually satisfactory than sex in a relationship.
A few years ago a study by a German sex researcher, Dr Werner Habermehl, found that redheads have more active sex lives than their blonde and brunette sisters. According to Habermehl, women who colour their hair red are subconsciously signalling that they are on the look-out for a new partner or eager to improve their sex lives. As a ginger person, this was a study I could get behind. I was less delighted, however, when Angela Scanlan’s documentary Oi! Ginger! looked at a UK study which found that men on the prowl were six times more likely to approach a blonde than a redhead, and that gingers were significantly less popular than brunettes too. So I am either a ravishing redhead with a steamy sex life, or a ginger minger and sexual no-go zone unless a man is three sheets to the wind — or possibly both, depending on whether I’m in Berlin or Bristol.
Things are just as confusing when scientists examine male sexual selection. Various studies have found that men lower their standards entirely for casual sex; or that they are most likely to have a one-night stand with a woman who is in the most fertile stage of her menstrual cycle; or a woman wearing red; or a woman with big breasts. Some studies have found that both men and women are attracted to people who are lively, popular and flirtatious, while others claim that men prefer quiet, reserved, shy ladies.
Here’s something most of us will find reassuring — a few years ago I read that average-looking men and women are more popularthose with luminous good looks. The researchers concluded that this was because very beautiful people were seen as unapproachable. Unfortunately a few weeks later I read that better-looking people, both male and female, tended to have a greater number of former sex partners since they had more options than the average-looking among us.
If you’ve read this far, it probably won’t surprise you to hear that other studies looking at sexual histories discounted a person’s attractiveness and instead concentrated on their personalities. Some psychologists regard a large number of former sexual partners as indicative of a selfish and shallow attitude towards sex; others have concluded that the more empathetic and warm-hearted we are, the more likely we are to have a significant number of notches on the bed post. In a study published recently, which I look at in this issue’s Sex O’Clock News, the way our brains process visual stimuli may make us more or less likely to pursue new sex partners. So is it prettiness, personality or brain processes that make us choose to bump uglies with that special or not-so-special man or woman? Who the hell knows?
Some of these contradictions are the result of flawed methodology. Either the study was badly designed or the researchers accidentally overlooked an important variable, used a leading or unclear question, or failed to take into account our willingness to overlook experiences that don’t square with our sexual identities. For example, one study found that if they asked heterosexual men if they ever had a homosexual experience, they got significantly more “no” answers than if they asked if the participants had ever received a blowjob from a man.
If I have learnt anything from sexual research it is this: the more I read, the less I seem to know. The reasons we have sex, and the criteria we use to choose our partners, are anything but straightforward. People are complicated, desire is an intricate knot of physical, emotional and psychological impulses, and sex and romance are a messy business. It doesn’t make things easy, but it sure as hell makes 'em interesting.
That’s no bad thing — after all, no matter who it is with, where, when or how often, the golden rule is that sex should never be boring.