Daniel Nettle’s book, Happiness, devotes a chapter to explaining the distinction between wanting something, and liking it once you get it. Wanting and liking are separate. We can want something but not enjoy it, or we can not want something but then find we like it when we get it. Combined with our poor judgements of our future emotions, this can lead people to some pretty strange decisions.
It is mainly through studies of drugs that we know this. In one study, heroin addicts were asked to press a lever 3,000 times to receive one of three possible injections – a low dose of morphine, a moderate dose of morphine, or just saline. Then they were asked to rate how much they enjoyed each shot. The group that received saline wouldn’t not press the lever again; they did not find the injection to be pleasurable and weren’t interested. In the group that received a moderate dose, they found the injection pleasurable and went on to work the lever for another shot. But the group receiving only a low dose was the interesting one. They too press the lever again, to get another shot – even though they did not find the dose high enough to be pleasurable. It was enough to trigger the wanting system, but not the liking system.
People are not always looking for pleasure. We also look for status, power, creativity, meaning, and lots of other things. The implication is, something that gives us a little advancement in one of these areas, (say, a job that gives us a higher status at work), might activate the wanting system, but not the liking system (for example, we realise we don’t like management or responsibility).
Why would the wanting system lead us to strive after things that we won’t? Well, the brain doesn’t much care how happy you are, as long as you’re surviving. We might not like our higher status job, but it boosts our ability to survive. Millions of years ago there was no welfare state, no agriculture, no civilisation. We roamed in tribes where higher status individuals had higher chances of survival. Although life is very different now, we have the same instincts.
Unless we’re able to consciously realise the times when something we want isn’t something we like, we might end up making the same mistakes over and over.