Before you start

This is a short book and you can read it in two or three sittings. It's about one habit. When you get something wrong, and often when you haven't, you speak to yourself in a way you'd never speak to another person. You call yourself an idiot. You ask what's wrong with you. You go over your failings in the dark. Nobody hears it, and you've done it for so long that it seems less like a habit than like simply knowing yourself.

I'm going to argue three things. The first is that the habit was learned, usually early and usually from somebody else, and that you keep it up for reasons that seem sound. Chief among them is the belief that it keeps you in line, and that without it you'd become lazy, careless and pleased with yourself. The second is that it doesn't do that. The research on people who are hard on themselves finds that they make less progress towards their goals, judge their own performance less accurately, and find it harder to face their mistakes. I'll set that out and give its limits. The third is practical. When you get something wrong, you talk to yourself the way you'd talk to a friend who'd done the same. Chapters 15 to 17 cover how.

Nothing in this book asks you to lower your standards, make excuses, or tell yourself you're wonderful. I'm not recommending affirmations in the mirror. If you've hurt someone, you should feel it and put it right. The argument is about the difference between correcting yourself and attacking yourself, and I'll argue that the attack gets in the way of the correction.

Four cautions.

If you've felt low, hopeless or worthless for most of the day, every day, for more than two weeks, that may be depression, and harsh self-criticism is one of its symptoms as well as one of its causes. The NHS advice is to see a GP. A book isn't a treatment for depression.

If the things you say to yourself include wanting to hurt yourself, or that others would be better off without you, please seek help now. Call 111, or 999 in an emergency. The Samaritans are on 116 123 at any hour.

This book is about your own thoughts, in your own inner voice. If you hear a voice that seems to come from outside you, or that other people can't hear, that's a different thing, and you should talk to your GP about it.

And if the harsh voice in your head is recognisably that of someone who mistreated you, a parent or a former partner, a short book may not be enough. A therapist can help with that, and chapter 17 says a little more.

The notes at the back give my sources and their limits. Where I'm giving my own reasoning and not a finding, I'll say so.