The Power of Habit by Charles Duhigg: Summary & Notes

Rated: 8/10

Available at: Amazon

ISBN: 0385669763

Related: Atomic Habits, Thinking, Fast and Slow


Until reading James Clear’s Atomic Habits, this was the best book on habit formation (and breaking) I had read.

Duhigg clearly describes the research behind habit formation, as well as breaking down habits into clear parts. He then uses this to teach how we can successfully form new habits by substituting components.

No doubt some of these ideas informed James’s book as well.

I would read Atomic Habits first, but if you want another perspective, you’ll gain valuable insight from this book as well.


Chapter 2: The Craving Brain: How to Create New Habits

  • First, find a simple and obvious cue.
  • Second, clearly define the rewards.
  • Once our brains learn about a reward, we begin to anticipate it. Only when your brain starts expecting the reward will we begin to have a habit that lasts.

Chapter 3: The Golden Rule of Habit Change: Why Transformation Occurs

  • That’s the rule: If you use the same cue, and provide the same reward, you can shift the routine and change the habit. Almost any behaviour can be transformed if the cue and reward stay the same.
  • Say you want to stop snacking at work. Is the reward you’re seeking to satisfy your hunger? Or is it to interrupt boredom? If you snack for a brief release, you can easily find another routine - such as taking a quick walk, or giving yourself three minutes on the internet - that provides the same interruption without adding to your waistline.
  • We know that a habit cannot be eradicated - it must, instead, be replaced.
  • And we know that habits are most malleable when the Golden Rule of habit change is applied: if we keep the same cue and the same reward, a new routine can be inserted.
  • But that’s not enough. For a habit to stay changed, people must believe change is possible. And most often, that belief only emerges with the help of a group.

Chapter 4: Keystone Habits, or the Ballad of Paul O’Neill: Which Habits Matter Most

  • Small wins fuel transformative changes.
  • The second way that keystone habits encourage change: by creating structures that help other habits to flourish.

Chapter 5: Starbucks and the Habit of Success: When Willpower Becomes Automatic

  • Dozens of studies show that willpower is the single most important keystone habit for individual success.
  • Willpower is like a muscle that can be built, and just like a muscle, can be depleted.
  • To make willpower a habit, choose a certain behaviour ahead of time, and then follow that routine when an inflection point arrives.

Chapter 7: How Target Knows what you want before you do: When Companies Predict (and Manipulate) Habits

  • Whether selling a new song, a new food, or a new crib, the lesson is the same: If you dress a new something in old habits, it’s easier for the public to accept it.

Chapter 8: Saddleback Church and the Montgomery Bus Boycott: How Movements Happen

  • When sociologists have examined how opinions move through communities, how gossip spreads or political movements start, they’ve discovered a common pattern: Our weak-tie acquaintances are often as influential - if not more - than our close-tie friends.
  • For an idea to grow beyond a community, it must become self-propelling. And the surest way to achieve that is to give people new habits that help them figure out where to go on their own.

Chapter 9: The Neurology of Free Will: Are We Responsible for Our Habits?

  • As I’ve tried to demonstrate throughout this book, habits - even once they are rooted in our minds - aren’t destiny. We can choose our habits, once we know how.
  • However, to modify a habit, you must decide to change it. You must consciously accept the hard work of identifying the cues and rewards that drive the habits’ routines, and find alternatives. You must know you have control and be self-conscious enough to use it - and every chapter in this book is devoted to illustrating a different aspect of why that control is real.

Appendix: A Reader’s Guide to Using These Ideas

The Framework:

  • Identify the routine
  • Experiment with rewards
  • Isolate the cue
  • Have a plan

The point is to test different hypotheses to determine which craving is driving your routine.

  • As you test four or five different rewards, you can use an old trick to look for patterns: After each activity, jot down on a piece of paper the first three things that come to mind when you get back to your desk. They can be emotions, random thoughts, reflections on how you’re feeling, or just the first three words that pop into your head.
  • What’s more, studies show that writing down a few words helps in later recalling what you were thinking at that moment.
  • Our lives are the same way. The reason why it is so hard to identify the cues that trigger our habits is because there is too much information bombarding us as our behaviours unfold.

To identify a cue amid the noise, we can use the same system as the psychologist: Identify categories of behaviours ahead of time to scrutinize in order to see patterns. Luckily, science offers some help in this regard. Experiments have shown that almost all habitual cues fit into one of five categories:

  • Location
  • Time
  • Emotional state
  • Other people
  • Immediately preceding action

So if you’re trying to figure out the cue for the “going to the cafeteria and buying a chocolate chip cookie” habit, you write down five things the moment the urge hits (these are actual notes from when I was trying to diagnose my habit):

  • Where are you? (Sitting at my desk)
  • What time is it? (3:36pm)
  • What’s your emotional state? (Bored)
  • Who else is around? (No one)
  • What action preceded the urge? (Answered an email)

Put another way, a habit is a formula our brain automatically follows: when I see CUE, I will do ROUTINE in order to get a REWARD.

To re-engineer that formula, we need to begin making choices again. And the easiest way to do this, according to study after study, is to have a plan. Within psychology, these plans are known as “implementation intentions”.

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