Sex, Drugs and Chocolate: The Science of Pleasure. Paul Martin

few minutes. The animal could eat the accumulated chocolates at any stage, but as soon as it ate any it would receive no more. If, on the other hand, it contained its desire, it was allowed to eat all twenty pieces at the end. Chimpanzees adore chocolate, as any highly intelligent being would. Nonetheless, they proved quite capable of resisting the lure of immediate gratification in order to win a bigger chocolaty reward later.

      Much of what we might think of as pleasure is actually the anticipation of pleasure or the desire for something we believe will be pleasurable. Charles Darwin highlighted this distinction in The Expression of the Emotions in Man and Animals, published in 1872. He noted that humans and other animals often express feelings of pleasure in the form of movements and sounds – as, for example, when young children laugh, clap their hands and jump for joy. However, Darwin observed that:

      It is chiefly the anticipation of a pleasure, and not its actual enjoyment, which leads to purposeless and extravagant movements of the body, and to the utterance of various sounds. We see this in our children when they expect any great pleasure or treat; and dogs, which have been bounding about at the sight of a plate of food, when they get it do not show their delight by any outward sign, not even by wagging their tails.

      Freud also recognised that there is more to human motivation than the simple principle of seeking pleasure and avoiding pain in the here and now. In a later work entitled Beyond the Pleasure Principle, he wrote: ‘The most that can be said is that there exists in the mind a strong tendency towards the pleasure principle, but that that tendency is opposed by certain other forces or circumstances, so that the final outcome cannot always be in harmony with the tendency towards pleasure.’ Recognising the anticipatory nature of human motivation, Freud described it as ‘hedonism of the future’.

      Another embarrassing flaw in the simple pleasure principle is that many of us spend surprisingly little of our time doing the things that actually give us the most pleasure. This is why most people feel significantly better if they deliberately make themselves spend more time doing pleasant things. Several psychological studies have demonstrated that instructing people to adopt a conscious strategy of engaging more in pleasant activities really does lift their mood, even if they were not depressed to begin with. ‘Pleasant activities training’, as it is called, is demonstrably more effective at raising mood than physical fitness training or daily sessions of introspection. Now, you might regard the revelation that doing nice things makes people feel better as a statement of the blindingly obvious. What is less obvious, however, is why most of us do not already behave in this way. If our behaviour really were driven by the simple pleasure principle of doing what feels good now, our lives should already be crammed full with pleasurable activities. The fact that this is not generally the case is further proof that the truth is more complex.

      The simple pleasure principle is clearly not sufficient to explain the intricate reality of human and animal behaviour. We will see later that much of what we do is driven not by pleasure but by desire. Meanwhile, let us take a closer look at the trio responsible for so much of human pleasure: sex, drugs and chocolate.

       THREE Sex

      It is truly amazing just how much you can put up with when you are getting regular sex.

      NIGEL SLATER, Toast (2004)

Sexy beasts

      Sex may be blissful, but biologists are still not sure why it evolved in the first place. It is, after all, a strange way for animals to reproduce themselves, if you think about it. In their efforts to understand the evolution of sexual behaviour, biologists have paid surprisingly little attention to the role of pleasure. This may be because, in the natural world, sex is mostly about procreation rather than fun. Even among the big-brained mammals, most females are interested in sex only when they are fertile, around the time of ovulation. They may copulate frequently and energetically during these fertile phases, but sex is unlikely to be the main source of pleasure in their lives. Much the same must be true of many male mammals, for whom the sexual act can be remarkably brief. Rabbits and rams, for example, usually ejaculate within a few seconds of starting intercourse.

      We humans belong to a small coterie of species in which sexual behaviour is not biologically shackled to reproduction. Our willingness or desire for sex has little to do with female fertility. We may have sex more or less throughout the menstrual cycle and carry on doing it during pregnancy and after menopause. Most human sexual activity takes place when reproduction is impossible, and in that sense it is largely recreational. Dolphins share this unusual characteristic with us, as they too continue to have sex throughout the female’s reproductive cycle. Dolphins are also enthusiastic practitioners of masturbation, as we shall see in chapter 10. However, our main rival for the title of sexiest beast on the planet is the bonobo (Pan paniscus), a species of African ape that looks very similar to the chimpanzee.

      Bonobos are our closest biological relatives. They live in the dense and inaccessible rainforests of the central Congo basin, which makes it difficult for biologists to study them in the wild. One of their many attractive characteristics, besides being very intelligent and highly sociable, is that they have a lot of recreational sex. Several times a day is normal, under the right conditions. Like us, they remain sexually active regardless of whether the female is fertile and they have an extensive sexual repertoire. In addition to conventional male – female intercourse, bonobos go in for male – male and female-female couplings, group sex, masturbation, oral sex and kissing with tongues. Female bonobos often have close encounters with other females: after embracing each other, one female lies on her back, the other climbs on top and they vigorously rub their genitals together. Biologists refer to this as ‘g – g-rubbing’, as in genital – genital. Just about the only form of sexuality that bonobos do not regularly indulge in is copulating with their own children.

      Bonobos are not the only primates to engage in girl-on-girl action. Female stump-tailed macaques also achieve orgasms through female-female couplings, just as they do from having sex with males. We know this thanks to scientists who secreted miniaturised radio-telemetry equipment in hard-to-reach places in the monkeys’ anatomy. Measurements obtained in this way from stump-tailed macaques while they are having sex have revealed that their orgasms involve much the same profile of physiological changes as those observed in human females, including intense uterine contractions and sharp increases in heart rate. Other female primates have their own ways of enhancing sexual pleasure. For instance, female sooty mangabeys, a species of monkey from West Africa, sometimes use their hands to stimulate their own genitals while they are having sex.

      In bonobo society, females often dominate males, initiate sex and form powerful coalitions. Female bonobos exercise a lot of control over when, how and with whom they have sex. They use sex as a social tool as well as a source of pleasure. When two unfamiliar tribes of bonobos encounter each other in the forest, females from each tribe will often initiate sex with males from the other tribe as a way of breaking the ice. Perhaps as a result of all this pleasurable sex, bonobos are generally friendly towards each other. There is little overt conflict. Biologists have pointed out the contrast between these sexy, peaceful apes and their closest biological relative, the chimpanzee. Chimps have less recreational sex than bonobos and their society is more male-dominated. They are also more aggressive. When two chimpanzee tribes meet in the wild, they are more likely to make war than make love. The outcome is often violent and bloody. All of this has led the bonobo’s admirers to regard them as the hippies of the ape world. One observer described them as equal parts dolphin, Dalai Lama and Warren Beatty.¹ Sadly, only a few hundred thousand of these wonderful animals are left on the planet. So how do we humans compare?

      We belong to a very sexual species that is capable of being even more lustful and inventive than the bonobo. Sex is self-evidently a prominent feature of human life, albeit one that is expressed (or repressed) in many different ways. A national survey conducted in the UK at the end of 2005 found that people rated sex as the second most important