The Power Of Habit (Book Summary)

At A Glance

Our brains constantly try to save effort and simplify difficult activities into routines. The Power of Habit demonstrates how every activity we do is dependent on these “autopilot” habits; the key to losing weight, become more productive, and achieving your goals is in understanding how these habits work and how to change them.

Back Story

The author was inspired by a story from Kufa, Iraq. Violence in this city would always begin with a small gathering and grow in size due to food vendors feeding the protestors. An Army Major noticed this cycle and interrupted it by prohibiting the food vendors from selling in the central plaza. With no food available, the next time the protesters came together, they became hungry and disbursed. (The story is a metaphor for the cycle of habit each of us participates in and how by interrupting a key part of it, we can cause real change.)

Note: About 40% of everything we do is on “autopilot,” meaning that we aren’t really making the decisions; we’re just following our habits.


The book breaks all habits into a single three-step process: CUE, ROUTINE, and REWARD.

1. The cue is analogized as the trigger or switch that lets your brain know when a habit should start. (Examples: An Alarm Clock, A Toilet Flush, anything distinct enough where your brain can know exactly what to expect afterward)

2. The routine is the habit itself; it’s the process or set of behavior your brain does automatically after it gets the cue to do so. The cue is the alarm clock going off; the routine is your hand quickly reaching to turn it off.

3. The reward is the way your brain determines if it did a good job or not; if a habit consistently ends with pain or discomfort, then your brain will stop doing it automatically and try to find a new process. After you turn your alarm clock, you’re reward with peace and quiet and a few more minutes of sleep.

Following this same simple process, the author outlines how anyone can create their own habits as long as they have two things.
1. A simple and obvious cue
2. A clearly defined reward

Armed with a simple cue, and a clear reward, you need to adopt a new routine. The goal is to get your brain to crave this new habit so that it can receive the reward.

Note: Duhigg calls this process: keeping everything about the cue, routine, reward cycle exactly the same except for changing what the routine is, the golden rule. 

In chapter 5, the author writes about a willpower experiment performed on 29 people over 4 months. The participants kept a log of everything they bought. Over time, their spending habits improved; however, other habits changed as well like smoking, alcohol consumption, and work productivity. As the participants strengthened their willpower in one part of their lives, other parts naturally followed.