Nir Eyal writes:

As part of a French study, researchers wanted to know if they could change how much money people gave to a total stranger using just a few specially encoded words. They discovered a technique so simple and effective it doubled how much people gave.

The turn of phrase has been shown to not only increase how much bus fare people give, but was also effective in boosting charitable donations and participation in voluntary surveys. In fact, a recent meta-analysis of 42 studies involving over 22,000 participants concluded that these few words, placed at the end of a request, are a highly effective way to gain compliance, doubling the likelihood of people saying “yes.”

What were the magic words the researchers discovered? The phrase, “but you are free to accept or refuse.”

The “but you are free” technique demonstrates how we are more likely to be persuaded when our ability to choose is reaffirmed. The effect was observed not only during face-to-face interactions, but also over email. Though the research did not directly look at how products and services might use the technique, the study provides several practical insights for how companies can influence customer behavior.

Product inspiration:

- When our autonomy is threatened, we feel constrained by our lack of choices and often rebel against doing the new behavior. Psychologists call this “reactance.”

- To change behavior, products must ensure the user feels in control. People must want to use the service, not feel they have to.

- Attempting to create entirely new behaviors is difficult because these actions often feel like “haftas.” For example, unless someone already has a habit of counting calories, a diet tracking app can feel alienating, telling the user what to do and neglect to provide opportunities to get back on track if they slip-up.

- However, by making an existing behavior easier to do, a product can imply a choice more likely to be accepted. By making the existing behavior simpler and more rewarding, products give users the choice between their old way of doing things or porting their habits to the better, new solution instead.

- By catering to existing routines, products stand a better chance of changing user behavior as they move people to increasingly complex actions and new habits over time.