"I'd stop if it were really dangerous"

This one's a comfort rather than a claim. You're a sensible person. If the peek were really as bad as the adverts say, you'd have stopped, and the fact that you haven't means some part of you has judged it and found it survivable. Your behaviour is the evidence of your assessment.

Atchley's survey of young drivers cuts through that. Ninety-two per cent said they read texts while driving, eighty-one per cent replied, seventy per cent started them. Two per cent never did it under any circumstances. And the same drivers rated all of this as very risky, riskier than talking on the phone. Their perception of the risk was a very weak predictor of whether they started texts and had no relationship at all to whether they read or replied. Knowing it was dangerous and doing it lived side by side without touching.

Heidi Nemme and Katherine White found the same in a study of a hundred and sixty-nine students, with a follow-up a week later. What predicted texting wasn't perceived control over the behaviour. It was attitude, what the person's friends did, and what they felt they ought to do. Intention predicted the behaviour. Believing it was risky didn't move much.

So the belief that you'd stop if it were really dangerous has the mechanism wrong. Knowing doesn't stop the habit, because the habit isn't run by what you know. It's run by the buzz, the hand, and the thousand times nothing happened. That's why the adverts haven't worked on you, and it's why this book isn't trying to be one. You already know. The knowledge is filed. The hand doesn't check the file.

Which means the fact that you haven't stopped isn't evidence that it's fine. It's evidence that knowing was never going to be enough, and that the thing that changes the habit has to be something other than more knowing. Chapters 18 to 21 are that something, and none of them ask you to be more convinced.