"It helps when I'm upset"

Comfort is the hardest of the three jobs to write about, because the feeling behind it is the most real. When you came off the phone to Claire you were hurt and tired, and what's wrong with your mum's care can't be fixed at nine in the evening. The tin was there, and reaching for it felt kind.

So I'll begin with the evidence, which is kinder than you might expect.

Heather Scherschel Wagner, Traci Mann and their colleagues at the University of Minnesota ran four experiments on comfort food. First they asked each volunteer what their own comfort food was, which for many was chocolate, ice cream or biscuits. Then, in the laboratory, they showed the volunteers film clips chosen to make them sad. Afterwards, on one visit, each person was given their comfort food. On another visit they got something different. In one experiment it was a food they liked equally but didn't consider comforting, and in another it was a neutral snack. In two of the experiments they were given nothing at all, and just sat for a few minutes. Their mood was measured throughout.

After the comfort food, people's moods improved. They improved just as much after the other foods. And they improved just as much when people ate nothing. The researchers' summary was that people may be giving comfort food credit for mood effects that would have happened anyway.

I think this is one of the most useful findings in the book. It doesn't say that your sadness is unimportant or that you shouldn't seek comfort. It says that a bad feeling brought on by a bad phone call starts to ease within minutes, whatever you do, and that whatever you happen to be doing at the time gets the credit. For years the thing you were doing was eating biscuits. So you've got a large store of memories in which you felt dreadful, opened the tin, and felt somewhat better. Each of those memories is accurate, but the tin didn't cause the recovery in any of them.

Macht's three minutes from chapter 4 fits in here. The biscuit does add a small, real pleasure on top of the recovery that was already coming. Then it's gone, and the recovery carries on without it.

Next, look at what the tin leaves behind. When you ate four biscuits in front of the television on Thursday, you ended the evening with the original upset somewhat faded, as it would have been anyway, and with a second bad feeling on top, which was the self-disgust on the way to bed. The comfort added a new problem by ten o'clock, and you'd have been better off without it.

There's also what the tin displaces. Comfort, in the full sense, is what a person gets from being heard by someone, or from a bath, a walk, a cry, or writing down what they'd like to say to their sister and not sending it. Those things take a bit more effort than lifting a lid, which is why the tin wins. But some of them deal with the upset itself, and the biscuits don't. After four biscuits the situation with Claire is unchanged, and you haven't told anyone how it made you feel.

An honest objection is that sometimes there's nobody to ring and you haven't the energy for a walk. That's true, and on those evenings I'd rather you were kind to yourself than heroic. Wagner's volunteers who ate nothing didn't do anything heroic either. They sat for a few minutes and let it pass. That option is always open, and nothing is required of you for it. You can sit on the sofa and feel rotten for ten minutes, knowing that it's already easing.

If you find that you're upset most evenings, the biscuits aren't your main problem. If a low mood has lasted for weeks, that's something to take to a GP.