At, we get a consistent message from our users. They're "addicted" to the Challenge. Recently, we took a look at the best-selling book The Power of Habit by Charles Duhigg to try to understand why.

Duhigg, who is an investigative reporter for The New York Times, synthesizes new brain research to outline a phenomenon he calls the habit loop: Your brain responds to a cue, which tells it to embark on a routine, which ends when the brain registers a reward. As your brain develops a craving for the reward, it internalizes the routine such that your brain actually shuts off while the routine is going on. Thus, Duhigg explains, the first time you back down the driveway, the complex process "required a good dose of concentration," but after it becomes a habit, "you pull onto the street with hardly any thought." If you have a cookie habit, you might find yourself reaching mindlessly for one after lunch, no matter how many resolutions you have made not to.

Duhigg argues that habits control the way we eat, exercise, take care of ourselves, spend money, run companies, and organize societies. In fact, he suggests, habits are so powerful, the only way to break a bad one is to institute a new habit in its place, citing as examples alcoholics who swap the going-to-an-Alcoholics-Anonymous-meeting habit for the having-a-drink habit, or Target executives who noticed pregnancy is a time when women form shopping habits that last for life, and thus began sending pregnant women prenatal vitamin coupons to make sure Target was a part of their changed routine.

Apply Duhigg's approach to the Challenge and it's not hard to see why the Challenge is so sticky. Each question serves as a habit loop unto itself, where:

  • Cue: seeing a question
  • Routine: answering it
  • Reward: getting it right/earning achievements and points.

Every time you finish a complete the loop the next question, or cue, is waiting, which helps you keep going forward to learn more.

Of course, playing the Challenge is not the only way you can use the power of habit to systematically improve your vocabulary. Think about what habit loop is triggered when you encounter a word you don't know. Do you skip over it? Stop and look it up in the dictionary? Underline the word? See if you can't replace whatever habit is in place for you with this new routine:

  • Cue: When you see a word you don't know...
  • Routine: Grab your smartphone, look up the word in the Dictionary, and add the word to a Vocabulary List of words you're working on.
  • Reward: Watching your list of words you've mastered grow.

Do you have a vocabulary building habit? Share it with the community in a comment below.