Designing for Behavior Change

Chapter 1. How the Mind Decides What to Do Next

The Deliberative and Intuitive Mind

Our society has a polarized, contradictory view of how the mind works—either we think we’re careful, rational people, or we’re just emotional wrecks that are lucky to get through the day alive. Sometimes we even hold both views at the same time—we consider ourselves to be rational, but those in opposing political parties or in different departments at work are blinded by their emotions.^[9]

Well, the truth is that both are absolutely true—and they are true at the same time, in every single one of us. That fact is essential to understanding how to design products that change behavior.

We have two modes of thinking in the brain—one is deliberative and the other is intuitive. Psychologists have a well-developed understanding of how they work, called dual process theory.^[10] Our intuitive mode (or “emotional” mode; it’s also called “System 1”), is blazingly fast and automatic, but we’re generally not conscious of its inner workings. It uses our past experiences and a set of simple rules of thumb to almost immediately give us an intuitive evaluation of a situation—an evaluation we feel through our emotions and through sensations around our bodies like a “gut feeling” ([ref41]). It’s generally quite effective in familiar situations, where our past experiences are relevant, and does less well in unfamiliar situations.

Our deliberative mode (aka our “conscious” mode or “System 2”) is slow, focused, self-aware ...