How to Change
Katy Milkman offers practical ways to change behavior. Some of the book’s supporting stories need correction, and a deadline paper it cites has since been retracted.
Read the reviewLearn
Understand behavior change.
Why is behavior change so hard? Learn what shapes people’s actions, why common advice falls short, and how to find approaches that fit the person and the situation.
Start the first lesson
Start here
Five lessons on behavior change
You might want to exercise more, help customers use a product, or change how your team works. Before choosing a technique, it helps to understand what you’re asking people to do—and whether it makes sense for them.
These lessons connect the research to those practical questions. Start with the change you want, examine the evidence, consider the people involved, and compare possible actions before trying one. Each lesson includes examples, sources, and a short exercise.
Start with the outcome
Choose what you want to accomplish before deciding what people must do.
Read the evidence before the promise
Find out what a study actually supports and whether the difference is worth acting on.
Understand the person and situation
Choose with the person’s enduring tendencies and actual circumstances in mind.
Build a behavior menu
Compare different routes to the same outcome and choose an action worth trying.
Try, observe, and adapt
Try the behavior in your actual life, then use what happens to make the next choice.
Evidence Library
Which behavioral science findings hold up? Read 14 evidence reviews that compare original studies with replications, later research and retractions.
Evidence-based book reviews
We examine the claims, check the sources, and assess the practical advice in popular psychology and behavioral science books.
The Psychology of Money
Morgan Housel offers useful advice about saving, patience, and preparing for setbacks. His claims about what matters most in wealth and happiness are less reliable.
Read the review
The Let Them Theory
Mel Robbins’s acceptance-and-action idea is most useful in ordinary life. Its scientific and clinical extensions need much more care.
Read the reviewBrowse subjects
Explore a topic
Have a particular question? Explore personality, habits, decision-making, and the evidence behind behavior-change techniques. Each subject brings together lessons, guides, and reference material.
Foundations of behavioral science
What are you trying to accomplish, and what could someone actually do to get there? Start with those questions before choosing a behavior-change technique.
Reading the evidence
A published result can be real, small, and of little use to your decision. Learn to examine effect sizes, replications, and what a study actually measured.
Personality & individual differences
People have enduring tendencies, different interests, and everyday responsibilities. Learn how personality, skills, and circumstances affect which activities are likely to suit them.
Behavior selection & fit
Choose the behavior before designing the intervention. Compare alternatives by what they could accomplish, what they demand, and whether people actually want to do them.
Habits & effortful practices
Starting can become familiar while the work itself still needs attention. Learn which parts of an activity can become automatic and which still need thought and effort.
Interventions & behavioral design
Before choosing a nudge or prompt, ask whether its likely effect is worth the work—and whether a different behavior would serve the goal better. Examine the methods, the evidence, and the alternatives.
Decisions & social behavior
Why do people choose as they do, and how much can you change those choices? Learn the concepts without confusing an interesting explanation with a reliable intervention.
Applying & testing
Try a promising action in a real setting. Observe whether it happens and whether it helps, then decide what to keep or change.
Looking for a term?
Use the glossary for definitions and explanations, or search the full collection.