That’s the title of a terrific talk last night by Prof. Wendy Wood from the University of Southern California. An hour very well spent. Here’s the potted version:
Knowing what’s good for you doesn’t mean you’ll change your behaviour. The 5 A Day campaign launched in the UK in 2003. Awareness is great: 85% of people know they should eat 5 fruit and veg portions a day, but the consumption of fruit and veg hasn’t moved since the campaign started.
We don’t change habits because most of the time we’re not even thinking about what we’re doing. Instead we respond to cues, do what we’re doing automatically. In one study people were given stale popcorn to eat as they went into a cinema, and eat it they did - chewed through 70% of it. When the researchers tried it with people in a lab watching a film, did they eat stale popcorn? Some did, but plenty more turned their noses up. It’s all about the cues.

So, what is the secret? How can we make changes stick? Here’s what the evidence shows:
A survey of New Year resolutions found the ones people stuck at weren’t the good-for-you, ‘must exercise more’ type but the fun ‘see more friends every week’ type. Conclusion: we respond to rewards. If you want to start a new behaviour, make sure there’s a treat in it.
If you’re trying to change a long established habit, think tactically: what can you do to make that habit more difficult, more awkward, less automatic. What cues can you remove? If you want people to walk instead of cycling, lay bumps in the path. If you want people to take their cups to the kitchen and not leave them on the table, make the table tiny, and maybe a bit wobbly too.
But… it’s a complete myth you can change a habit in 21 or 30 days. It takes at least 66 days to change even a simple habit. So keep repeating, repeating, repeating.

We’d love to know what changes or new habits you’ve put in place, and how!