s anyone who counts a three-year-old among their acquaintances will know, there’s a fiery purity to the will of a small child that’s difficult to oppose. Once my son has figured out that there’s ice-cream in the freezer, and decided he wants some for dessert, my role is equivalent to that of the ineffectual UN diplomat attempting to persuade a major nation-state to stockpile fewer weapons: good luck with that. Yet frequently, on receiving the ice‑cream, he’ll decide to let it melt before consuming it – then forget about it completely. He wants ice cream, monomaniacally, with a force his little frame almost can’t contain. But he doesn’t like it so very much that some other absorbing activity can’t banish it from his mind. I only clearly grasped this distinction – and realised how it applies to me, too – when I encountered the findings of a study of coffee drinkers reported on the Research Digest blog. Using various psychological tests, researchers showed that “heavy” drinkers (those consuming three or more cups per day) had a much greater desire for coffee than those who consumed less of it, or none. But they took roughly the same, far lower level of pleasure as light drinkers when it actually came to drinking it. More serious addictions – to alcohol, or hard drugs – are characterised by a similar split between wanting and liking: you want the substance more and more, but like it less and less. And it’s been demonstrated that if you deprive people of a prize they want, they’ll desire it more; yet if they do then eventually acquire it, they’ll value it less. The ancient idea that what we desire isn’t necessarily what we enjoy has received support from modern neuroscience, which indicates that the two processes involve distinct circuits in the brain; dopamine, the so-called “pleasure chemical”, is probably better understood as a desire chemical, which can be triggered in huge quantities in the near-total absence of pleasure. (The mismatch is clearest, for me, with social media: seconds after succumbing to the desire to log on to Twitter, I realise, once again, that I won’t be having any fun there.) This makes evolutionary sense, too. From your genes’ point of view, it’s helpful that things like sex, or eating a meal rich in sugar and fat, should be pleasurable – but what’s really crucial is that they’re alluring. It’s much more important that you should want them, than that you enjoy them once they arrive. Just bearing this distinction in mind, as you trundle through the day, can be surprisingly empowering: there’s at least a chance you’ll remember, next time you’re gripped by the urge to check your phone, or have a second cocktail, or say something mean, that you might not enjoy it as much as you predict. It’s not that desire needs to be squelched, as some more joyless interpretations of Buddhism or stoicism might have it. It just needs to be understood as a not-useful guide to an enjoyable life. Wisely or not, I’ve also found myself surrendering to the three-year-old’s demands (even) more often. That way, wants arise and move through him, like a passing storm, and soon enough we’re back to enjoying ourselves. It’s a lot easier than trying to fight the weather. Read this In How Pleasure Works (2011) the psychologist Paul Bloom shows how even our strangest modern desires have their roots in our ancient survival needs.