Full disclosure: If you buy the book through the link, it won't cost you any more, but I'll get a few pennies. But my main motivation for doing this is to understand the book properly. What follows is my summary of the chapter.
Habits can be lethal, but no, he doesn't mean smoking.
Pilots have to go through a long check-list before take-off. These check lists reduce accidents, but they get so routine that occasionally the pilots will say “Check” without really checking. The results can be tragic, so there's a lot of research on how to avoid this. For example, moving the check-list from paper to computer halved the error rate.
Humans have such a strong tendency to see what they expect or want to see, especially when stressed. Give musicians music with mistakes in it, and by and large, they'll play correct notes instead. Most people don't spot spelling mistakes, especially in the middle of a word. [Sheila sez: no wonder it's so hard to proof read your own writing!] This sort of slip offers a fascinating window into how habits work.
We also substitute one action for another, like going to the fridge for milk and fetching orange juice instead. [Sheila sez: Am I the only one who actually put the orange juice in my tea?] We think we asked for coffee when we only thought about it, then get annoyed when coffee doesn't appear. [Sheila sez: I used to do that with letters. I'd write them in my head, and then be convinced I'd written them on paper and posted them.]
Another favourite is repeating part of a habit. Boil kettle, pour water into mug. Boil kettle again, pour water into full mug so it overflows and you have to mop up.
We do these things mostly in very familiar places, like the kitchen and bedroom. It's partly because we spend quite a lot of time there, but also because they're so very full of environmental cues to our habits.
Health and Safety has a bad reputation, but they became more effective when they stopped merely educating people. I remember when they ran TV adverts showing how very easy it is to go through a car windscreen if you're not wearing a seatbelt, and how very, very horrible it is if that happens. That persuaded people that they ought to wear seatbelts, but it didn't make them wear seat belts. The habit of shutting the car door and driving off was too strong.
So the psychologists started looked at what else was going on. And they found that environmental cues play a huge role in habits. Like the tragic case of the train driver who unconsciously developed the habit of driving off when he heard the guard ring the bell twice – missing out the vital “CHECK THE SIGNAL IS AT GREEN” part.
Explaining to people that smoking kills didn't stop people smoking. Banning them from smoking in certain places did, because it disrupted the habit. Check-lists also help.
Jeremy Dean finishes the chapter by saying, “We think of ourselves as biology, psychology and behaviour and neglect [snip] how we are embedded in our environments, both physical and social. Our habits [snip] also grow out of these. [snip] The situation has more power to control our habits than we think.