"While I don't know, I'm fine"

This is the belief at the centre of the habit, and it's hardly ever put into words, because it falls apart once you say it aloud. It goes like this. While nobody has examined the mole, I'm a healthy person with a mole. If I go, I might come out as a person with skin cancer. So the appointment is where the danger lies, and staying away from it keeps me safe.

But the appointment doesn't put anything into the mole. Whatever it is, it's that already. It was that in March when you first noticed, and it's been that every day since. If it's harmless, it's harmless now, and you've spent six months uneasy about a harmless thing. If it isn't, then it isn't harmless now either, and for six months it's had a free hand. The doctor's look changes nothing about the mole, only what you know about it. Knowing is the only route to reassurance if it's harmless, and the only route to treatment if it isn't.

Not checking the forecast doesn't keep the rain away. It only means you're out without a coat when it comes.

The feeling is persuasive all the same, and researchers have studied why. They call it information avoidance, and they've found that it follows a pattern. Alexander Persoskie, Rebecca Ferrer and William Klein looked at a nationally representative sample of American adults and asked who reported avoiding the doctor. Among people aged fifty and over, worry about cancer went with avoiding the doctor. But it did so only in people who also thought their chance of having cancer was high. The researchers' reading is that worry sends people towards information when they expect it to reassure them. It sends them away from information when they expect it to confirm what they fear.

Consider what that means. The people most likely to stay away were the ones who were worried and thought something might be wrong. Those are the very people a doctor would most like to see. The avoidance grows with the suspicion. If you've put off the mole for six months and the dentist for four years, and you were quicker about the dentist, that fits. You stayed away longest from the thing you're most afraid of.

The safe feeling comes from being able to say, truthfully, "as far as I know, I'm fine". The words "as far as I know" are doing all the work in that sentence, and the putting off keeps them true by making sure you know as little as possible. But your body isn't affected by what you know. You can't keep the thing away by keeping the news away.

There's an honest objection, and I'll come to it properly in chapter 5. "Perhaps I'd really prefer not to know. If it's something terrible and nothing can be done, I'd rather have the extra months of peace." I understand that. For now I'll make two points. The first is that you aren't having months of peace. You're having months of ten past three in the morning. The second is that "nothing can be done" is almost never the situation with something caught early, and it becomes more likely the longer the thing is left.

So the choice isn't between a safe state, in which you don't know, and a risky act, which is finding out. The risk is whatever is or isn't in your shoulder, and finding out is the only thing you can do about it.