The same person...the same face, the same body, the same lips, the same everything, from this day forward for the rest of your life. Can you handle it? According to some people, it's like hell on earth. Never before in our history has monogamy been such an issue. Before the middle of the twentieth century, no one every talked about it – you were generally married for life and if you were a man, you had a discreet little bit on the side. If you were a woman, well what does a woman care about sex, anyway, as long as she has a nice shiny new Frigidaire? During the sexual revolution, relationships didn't even last as long as the party did, and then you were on to someone new whose name you never quite got. And then came the eighties. Just when you thought everyone was cool with the idea of casual relationships, along comes AIDS and terrifies everyone back into the safety of long term monogamy. In the aftermath of all this, people in the twenty-first century have grudgingly accepted that committed relationships are probably the healthiest, even if they relish the idea as much as they do vegetarian bacon or tofu pizza. Monogamy may be good for us, but it doesn't mean we have to like it.

Is monogamy good for us? If you put any stock in studies undertaken by university scientists, you will find myriad examples of the benefits of marriage: 60% of single women reach the age of sixty-five, whereas 95% of married women do. Drug and alcohol abuse among 500 000 young test subjects dropped sharply among those who married. The University of Chicago recently conducted a study that showed married people make twice as much money, have twice as much sex and experience half the domestic violence as those who co-habit, and the numbers are likely even higher when compared to those who don't live together. But none of these statistics ever to seem to impress the legions of people who run a mile from marriage and consider monogamy too close to ‘monotony’ for their liking. For them, the sixties and seventies never ended. One taste of unfettered promiscuity and they're hooked, deadly diseases or not. These are the people who seek sanction for their philandering, and try to convince the rest of us that monogamy is unnatural, and ultimately unsustainable, and that we're all just kidding ourselves if we try to pretend otherwise.

One of their favourite arguments is that, as animals, it is our biological imperative to disseminate our DNA as widely as possible. We are driven, they maintain, to have sex with many, many partners in our lifetime so that we have the best odds of living on in the next generation. Most animals don't mate for life, they argue, and so neither should we. The simplest answer to this argument, before even getting into the obvious benefits of monogamy, is to realize that human beings are animals in physical form only. We have the most advanced brains on the planet, and our ability to reason, form concepts, to think, is unique to us. No dolphin ever landed a man on the moon. No gorilla, no matter how skilled at sign language, ever wrote a novel or charted the human genome or built a skyscraper. There is nothing on earth like a human being, and therefore no comparisons to animals are valid, especially when it comes to something as complicated and ultimately brain-oriented as sex.

While animals mate out of instinct – and sometimes at their own peril, like the various spider and insect males who give their lives to the female after mating – no human being ever mates without engaging their mind on some level. We actively choose to mate or not to, to reproduce or not to, and in every case, we never merely pursue someone simply because they are of the opposite sex. We have sex for more than procreation, whereas animals, with extremely rare exceptions, mate only during their fertile phases and only for the purposes of creating offspring. We also continue to love and care for our children even after they're weaned, which animals don't. Humans and animals are more different than we are alike; arguing that we should be as indiscriminately sexual as they are is ridiculous. The only argument that's left, then, is that promiscuity is just more fun. It's too boring, opponents of monogamy say. It just isn't exciting enough, being with one person all the time. Some groups have even christened this lifestyle with an official sounding name – “polyamory” – referring to themselves as simply “poly” and maintaining, quite honestly, that they do not see the value in exclusive relationships and would rather carry on several meaningful, if transient, relationships at once. It's more fulfilling, they claim, sharing your life with several partners, never being truly intimate with anyone.

I might actually believe them, I might actually defer to them and acknowledge that while it doesn't work for me, it obviously does for them. I might...if it wasn't so painfully obvious that these people are having anything but fun, are anything but excited, and are exactly what they claim to be avoiding: bored out of their minds. Promiscuous people are not happy. They are always looking for fulfillment around the corner, for excitement in the next encounter, for the bigger, the better, the more outrageous. They are never satisfied with what they have, but continue to strive toward something that is always out of reach. These people attempt to replace quantity with quality, growing tired with each new adventure and moving on, unsatisfied, to the next. Soon even the briefest of relationships aren't enough, then it must be a stranger. After strangers become boring, they decide two strangers, now that would be really exciting. But when that doesn't work, they have to reach lower and lower, degrade themselves even more, to find that next sexual thrill. When they aren't seeking newer and more outrageous adventures, they're busy running away from something – emotional problems, troubled pasts, flawed ideas about the validity of love... a happy and value-driven life. The inability to find and commit to someone wonderful is a serious character flaw, not a lifestyle that should be held up as a model of human behaviour. People who claim to enjoy being ‘poly’ must steel themselves against jealousy, an emotion that should, by rights, be a warning sign that they are doing something wrong. The fact that they feel it, or have to try desperately not to feel it when they have to share someone they care about with someone else, is probably the clearest indication there is that this lifestyle is not at all natural for human beings. The proof of this lies in the fact that if it came down to it, if they absolutely had to choose one person from their threesome or group to be with – just one – every single one of them would be able to make that choice. Everyone has a preference, even among people they care about. Everyone knows the one person they want to be with more than anyone else.

There's a loneliness that pervades those who simply flit from one person to the next, a sense that they are missing out on something profound and real. They know, deep down, that the height of love and the best kind of sex is found within long term, mutually exclusive relationships. They know, or should know, that good sex depends on it. And that's the bottom line when it comes to monogamy. Monogamy affords you the best sex of your life. If you understand, as I mentioned before, that sex for humans is as much about the mind as it is the body, then it makes perfect sense that the most fulfilling sex occurs within a mutually, loving, trusting relationship. Being with one person you love allows you a level of freedom and creativity that you can't possible enjoy with strangers. The intimate bond you form with the person whose character you love as much as their body allows you to explore the dominant and submissive aspects of your natures, without worrying about political correctness or misunderstandings. It allows you to grow, to experiment, to savour each experience and relive it, in reality or in a shared memory. It removes you from the realm of jealousy or competitiveness, and lets you live instead in a safe haven of sexual pleasure and freedom. It is the only kind of relationship that fosters primacy and privacy, the two most fundamental requirements of a satisfying, long term mutual love. When you slip into the arms of your only love, you know that you are welcome, desired, and that the tiny, subtle little things that give you the most pleasure are understood by your lover, and practiced with care. With most casual relationships, sex is a special occasion. It is the ultimate goal of the relationship, yet the one thing that always eludes the players, who chase after it and connive ways to get it and who ultimately only get to enjoy it with relative infrequency. Monogamy provides you with an opportunity to enjoy sex every day of your life, in every way, infusing even your non-sexual moments with a tinge of excitement and expectation. Spontaneity is much easier when you're married to your lover – if the mood hits when you're retiling the kitchen, you can make love right then and there. You certainly don't have to plan for a Saturday night date and spend all evening wondering whether it's going to happen and how good it will be. You can kiss the back of your wife's neck while she's working, or caress your husband's penis while you're watching TV, neither of which necessarily lead to sex but which reinforce your sensual bond with each other and keep the proverbial romantic fires lit. There's just no replacing that kind of constant, enriching, loving sexuality, no matter how many new faces or bodies catch your eye. Looking into the eyes of the person you admire most in the world only heightens the physical sensation of sex; looking into the eyes of a stranger only takes away from it. Your attitude towards monogamy makes you confront the question of which you want more.