One of the most important practical lessons from behavioural science is that we often fail to do what’s best for us, despite our best intentions – whether it be exercising more, eating more healthily, saving more money or stopping smoking. Many of the most commonly cited behavioural biases – loss aversion, uncertainty aversion, procrastination – lead to this kind of failure to act.
Thankfully, behavioural science also offers some suggestions on how to improve:
- Framing incentives as losses rather than gains tends to be more impactful. For example, if your reward for losing 10kg is to go to a concert, buy the ticket now – it will be harder to give it up than to never have received it. Roland Fryer and co-authors conducted an experiment where teachers were given their performance pay up-front and asked to pay it back if they failed to meet their goals. They found that compared to standard performance related pay this increased results by the same amount as reducing class sizes by around 8 pupils.
- Commitment devices can help save, or lose weight (though gym membership may not be an effective commitment device). Karlan and co-authors review a wide literature on commitment devices and find that they are often successful, even when they impose only psychological costs.
- Positive goals (“I will eat an apple every day”) are easier to keep than negative goals (“I will not eat ice cream”). Adriaanse and co-authors randomly selected female participants who wanted to lose weight and found that those who set goals “If I want to snack, I will eat a healthy snack” were significantly more likely to succeed in weight loss, and less likely to snack than those who set goals like “If I want to snack, I will not eat an unhealthy snack”.
- Making a public commitment can help people stick to their targets. For example, when people make a public commitment to weight loss (by having their name and target displayed on a bulletin board), on average lost 20% more weight than those who made a private commitment.
- Making small, short term goals can help reach larger, longer term goals. Townsend and Liu, conducted five experiments on people aiming to lose weight or save more money. They found that those who set goals that they perceived to be farther away were more likely to deviate from those goals by spending money or eating cookies.