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Susan Weinschenk Ph.D.

The Science of Habits

Think habits are hard to create or change? Not if you use the research.

Have you ever heard that it takes 60 days to form or change a habit? Well, that’s actually not true. I used to write about that being true, but new research and a mindset shift for me made me realize that habits can be very easy to create or change—if you understand the science behind habit formation and use that science when you are trying to change or create a habit.

Whether you realize it or not, a lot of your daily behavior is composed of habits. These are automatic behaviors that you do without thinking. You do them the same way every day.

Think about all the habits you have that you don’t even remember trying to create. Perhaps you put your keys in the same pocket when you walk out the door, or maybe you have a routine that you go through every weekday when you first wake up.

You probably have routines around hundreds of things:

  • How you leave the house for work
  • What you do as soon as you get to your place of work
  • How you clean your house or apartment
  • How you do laundry
  • How you shop for a gift for a relative
  • How you exercise
  • How you wash your hair
  • How you water your houseplants
  • How you take your dog for a walk
  • How you feed your cat
  • How you put your children to bed at night

And so on.

How did you end up with so many habits if they are so hard to create? If you understand the science around how habits are formed, you will see that there are some fairly simple things you can do that make habits very easy to form and even relatively easy to change.

For most people most of the time, habits are created unconsciously, and they are carried out automatically. Habits help us all to do the many hundreds of things we need and want to do in our lives. Because we can carry out a habit without having to think about it, it frees up our thought processes to work on other things. It’s a clever trick that our brains have evolved to make us more efficient.

It all started with saliva.

Let’s take a look at the science behind forming habits. If you ever took a psychology course, you probably have heard the name Ivan Pavlov. Pavlov won a Nobel prize in 1904 for his work in medicine. He researched the digestive system, working primarily with dogs. But while he was doing research on digestion, he discovered something that surprised him.

Pavlov was measuring the amount of saliva that dogs produce as part of digestion. He noticed first that dogs would salivate when they saw food, even before they tasted it. Then he noticed that if another event, such as a bell or the footsteps of the experimenter, was paired with the food, the dog would eventually start salivating at just the sound of the bell or the sound of the footsteps. This is called classical conditioning.

It goes like this: First you pair two things together, a stimulus (food) and a response (salivating).

Stimulus (food) results in Response (salivating)

Then you add an additional stimulus:

Stimulus 1 (food) + Stimulus 2 (bell) results in Response (salivating)

Over time you will be able to remove the original stimulus, and have just the additional stimulus elicit the response:

Stimulus 2 (bell) results in Response (salivating)

By now you are probably wondering what this has to do with you. You are probably not trying to create a salivation habit! Classical conditioning is the starting point for understanding automatic behavior and habits.

For example, let’s take a look at smoking. We start with:

Stimulus 1 (seeing cigarette) results in Response (light up and smoke the cigarette)

Then we add:

Stimulus 1 (seeing cigarette) + Stimulus 2 (feeling bored) results in Response (light up and smoke the cigarette)

Until we get:

Stimulus 2 (feeling bored) results in Response (light up and smoke the cigarette)

Keeping this original research in mind, let’s explore what we now know about creating or changing habits.

1. Small, specific actions are more likely to become habitual.

Let’s say you decide to create an exercise habit, and you tell yourself, “From now on, I’m going to get more exercise.” This is unlikely to turn into a habit, because it’s too general/vague, and it’s too big.

What about “I’m going to exercise three times a week.” That’s a little better, but still not specific enough. “I’m going to go for a walk every day after work” is better, because it is more specific. Or even, “When I get home from work, the first thing I’m going to do is change into my walking clothes/shoes and take a 30-minute walk.”

2. Making the action easy to do increases the likelihood that it becomes a habit.

Once you have identified the small, specific action, then you want to make that action easy to take. In the exercise/walking example, you will be more likely to engage in the habit if you make it easy. For example, put out your shoes and clothes right near the door so you see them when you get home.

3. Actions that involve physical movement are easier to “condition” into a habit.

With the walking/exercise example, that’s easy. You are going to reach out your arm and grab your workout clothes.

If you are trying to create a habit that is not very physical—for example, a habit where at the beginning of the workday, you pause and decide what are the most important things for you to do that day—then you will want to create a physical action to take. For example, have a special whiteboard near you and a special pen you use to do this task.

4. Habits that have auditory and/or visual cues associated with them will be easier to create and maintain.

One reason why using your mobile phone is so habitual is that it lights up when you have a message, and makes buzzing or chirping noises when there is a text. These auditory and visual cues grab our attention and increase the likelihood that we will develop a conditioned response.

The best way to change an existing habit is to create new one to replace it.

Let’s say you have a habit of coming home at the end of a workday, grabbing a soda, turning on the TV, and sitting on the couch. You’d like to stop doing that, because before you know it, an hour has gone by, and you haven’t started dinner or gotten any exercise.

How do you change that habit? You have to go back to the very beginning of the stimulus/response cycle and replace the current response with a different response.

This is what's happening with the existing stimulus/response:

Stimulus (walk in door) results in Response (grab soda, turn on TV, sit on couch)

To change this, decide what you want to replace it with. For example, let’s say you want to go for a walk as soon as you get home. The best thing to do is to position your walking shoes and perhaps a change of clothing right by the door you walk into. Then for a few days, purposefully and consciously grab the shoes and clothes, and put them on as soon as you walk in the door, and go for a walk.

Within seven days you will have conditioned the walk in door to a different response:

Stimulus (walk in door) results in Response (grab shoes and clothes, change, and go for walk)

Give it a try. Pick either a new habit you want to create or an existing habit you want to change. Next, figure out the stimulus and the response. Make sure the action is small, easy, attached to something physical, and, if possible, use a visual or auditory cue. Do the new habit for a week, and see what happens. You may be surprised at how easy it is to create or change habits.


The Power of Habit, Charles Duhigg,

BJ Fogg's site:


About the Author

Susan Weinschenk, Ph.D.,is a behavioral psychologist, author, coach, and consultant in neuropsychology.