Power of Habit: Why We Do What We Do in Life and Business – Charles Duhigg


This book focused on how habits are formed in the brain and how to change them. It focuses on “habit loop” which is comprised of three parts: Cue > Routine > Reward. Different chapters focus on different aspects of the loop and some key factors in changing habits. It ends with some discussion around larger social habits and how those can be changed.

Note: This book is almost entirely written through case study analysis. For the most part, I ignored the case studies in my summary. Mainly because I found them agonizingly long. But if you are excited about the case studies, obviously you should just check out the book. 

The Habit Loop: How Habits Work

From recent brain scanning techniques, it appears that habits are stored in a part of the brain separate from where memories are stored. They act as a way for the brain to perform certain functions with little to no thought, thus conserving the amount of energy the brain uses. Something cues the brain to start a habit, the routine is performed, and then some sort of reward occurs. Different cues start different habits.

The Craving Brain: How to Create New Habits

Habits are easiest to change by making a conscious plan to alter the reward or change the cues. But that alone isn’t enough. The brain has to develop a craving for the new reward, or it won’t stick. If you want to change your workout habits, maybe start going to the gym right when you wake up in the morning. Then when you are done, have some regular reward like a smoothie or a coffee. Waking up is the cue, and the drink is the reward. Think about the reward beforehand and focus on how much you want it because the anticipation will help drive your brain to crave the reward.

The Golden Rule of Habit Change: Why Transformation Occurs

Even when replaced, old habits seem to be fairly permanently etched in the brain. Belief seems to play a major role in complete transformation. For some, that is belief in something greater than themselves, such as God. But the focus of the belief doesn’t seem to matter as much as having the belief that change is possible. Changing habits doesn’t change the stressors in life that caused them in the first place. Someone who is several years sober may have a major life crisis like the passing of a loved one. Without the belief that permanent change is possible for them, this crisis is likely to drive them right back into the old habit loop. Belief works best in community, as the collective belief in change can help bolster your own.

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

Some habits appear to carry much greater importance than others. By working on one key habit, often other smaller habits will fall in line automatically. Focusing on building a single core habit such as working out or studying seems to give people the confidence to excel at other habits. Studies showed that people who successfully integrated a single habit also started eating healthier and exercising more without that being at all related to the core habit they were working on. Find one of these keystone habits that matters most, and focus on that. Everything else may become easier.

Starbucks and the Habit of Success: When Willpower Becomes Automatic

Willpower appears to be a finite resource that is expendable throughout the day. When it gets used up, we become irritable and less able to make decisions. Habits circumvent this mechanic by putting the brain on autopilot. If you have a fully functioning habit loop to work out, it no longer requires willpower to work out because a conscious choice is not required. So the more habits you employ, the more willpower you have available to do other things.

The Power of a Crisis: How Leaders Create Habits Through Accident and Design

Sometimes crisis provides a valuable opportunity for larger scale culture shift. Businesses and larger groups have habits as well. Right after a crisis is when large groups are most accepting of change because the crisis causes everyone to realize that change is required.

How Target Knows What You Want Before You Do: When Companies Predict (and Manipulate) Habits

Many companies are now tracking and analyzing data to send targeted advertising to consumers. The more they know, the more they can drive habits. Getting a couple expecting a baby hooked on shopping at a particular store for their baby supplies is likely to drive them to buy other things at that store as well. So hooking them on buying baby supplies at the store is key in order to start the habit early.

Saddleback Church and the Montgomery Bus Boycott: How Movements Happen

Movements seem to require a threefold blend of habit formation.

“–A movements starts because of the social habits of friendship and the strong ties between close acquaintances.

–It grows because of the habits of a community, and the weak ties that hold neighborhoods and clans together.

–And it endures because a movement’s leaders give participants new habits that create a fresh sense of identity and a feeling of ownership.”

Rosa Parks was such a powerful catalyst because she had a large number of friends and acquaintances in the community spanning the social and economic hierarchies.

The boycott took hold in part because of the weak ties and peer pressure of the community. And the boycott held because Martin Luther King Jr. and other leaders of the movement gave their followers new social habits of protesting peacefully and embracing persecution.

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

Is a woman who slowly descends into a gambling problem responsible for her habit? What if she was strong armed and pressured by a casino company?

Is a man who kills his wife in the throws of a sleep terror a murderer if he was asleep when he killed her? Is he responsible for his body’s habits?

One study on gamblers found that habitual gamblers brain’s triggered the “I won” dopamine rush for near wins, where non-compulsive gamblers brain’s triggered near wins as a loss.

Conclusion of this chapter is that if you know a habit exists, you have the responsibility to try to change it.

What to do about it

This is a methodology included in the appendix on how to identify and change habits.


  • Identify the Routine
    • Figure out the actions you take without thinking that you want to change.
  • Experiment with rewards
    • Try to identify what the reward is that you get at the end. Like an social engagement, sugar, etc. Then try to switch the reward and take note of how you feel.
  • Isolate the cue
    • Most habit cues fit into one of five categories: Location, Time, Emotional State, Other People, Immediately preceding action. Answer these questions about your habit routine for a few iterations of the habit.
      • Where are you?
      • What time is it?
      • What’s your emotional state?
      • Who else is around?
      • What action preceded the urge?
  • Have a plan
    • The best way to change a habit is to have a plan. Whatever the cue is for your habit, decide that when the cue happens you will perform some new planned action that has a similar reward.

Matt’s Takeaways

  • If I want to change bad habits, I need to identify the cues and rewards. Then make a plan to replace with a new habit. I have identified a cue and reward for my soda habit. A plan is pending because I am still trying to decide if I want to change. =)
  • If I want to change any habit, I have to believe that I can change. Belief is best centered in community. I am working on one of my bad habits and have gotten myself into a community of similar people who are trying to change. The community has definitely improved my belief that change really is possible.
  • Willpower can be bypassed by creating a plan and developing a habit. I am a habitual snoozer. I historically set my alarm for 15-30 minutes before I actually needed to wake up. After reading the section on willpower, I made a plan that when the alarm went off for a second time I would sit up and put my feet on the floor. If I wanted to sleep more after that, I could. This was so successful at getting me up in the first few days that I decided to try not snoozing at all. That was last night, and I got up on the first alarm this morning. So experiment results are pending, but promising.
  • I am working on developing a daily habit around writing. I wake up early, dress, stretch, engage in solitude or meditation, then write until I have to get ready for work. I reward myself for following the habit by checking off that I wrote that day in a habit tracking app (I have been using Loop Habit Tracker on Android if you are interested) and tracking a daily word count. With this new habit I have written around 4 blog posts and finished a 25k word novella manuscript. Woot!

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