In 1927, a class of university students and their professor visited a restaurant in Berlin, Germany. 
The waiter took their orders, including special requests, but refrained from writing them down.
This isn’t going to end well, they all thought.
But, after a short wait, all the diners received exactly what they’d ordered, without error.
After dinner, outside on the street, Russian psychologist Bluma Zeigarnik realised she’d left her scarf behind in the restaurant.
She returned, found the waiter with the photographic memory and asked him if he’d seen it.
But her question was met with a blank stare: He had no idea who she was or where she sat.
“How can you have forgotten” she asked him incredulously. “Especially with your super memory!”
The waiter replied matter-of-factly: “I keep every order in my head – until it is served.”
The Zeigarnik Effect
We seldom forget uncompleted habits; they persist in our consciousness and don’t let up, vying for our attention like little children, until we give it to them.
For example, If you’re writing as part of a daily writing habit and you’re interrupted, it’s likely you’ll want to return to is as soon as possible.
On the other hand, once we’ve completed a habit and checked it off our mental “to-do” list, it’s erased from our memory. This is known as “The Zeigarnik Effect” (after Bluma Zeigarnik).
In their book, Social Psychology and Human Nature, Roy Baumeister and Brad J. Bushman describe the Zeigarnik Effect as follows:
The Zeigarnik Effect is the tendency to experience intrusive thoughts about an objective that was once pursued and left incomplete. 
Almost 60 years after Zeigarnik’s research, Kenneth McGraw and his colleagues carried out another test of the Zeigarnik effect.
In it, participants had to do a really tricky puzzle; except they were interrupted before any of them could solve it and told the study was over.
Despite this, nearly 90% carried on working on the puzzle anyway. 
It seems to be human nature to finish what we start and, if it is not finished, we experience discomfort.
Do you see where this is going?
Implementing the Zeigarnik Effect
What the Zeigarnik effect teaches is that the secret to overcoming resistance to new habits is not only to start, but as Leo Babauta says: “make it so easy, you can’t say no”. 
When we think of starting a new habit, we tend to think of the entire sequence of actions that’s needed to necessitate its completion.
For example, it’s common to feel resistance when undertaking a new exercise habit (like strength-training). It’s simple: There are several steps needed to do it.
You have to pack you gym bag, travel to the gym, change into your workout clothes, warm up, exercise, warm down, shower, and change back into your normal clothes and travel back home.
The trick then, is not to think about the routine part of the habit loop (exercise), but to commit to the pre-requisite action in the sequence (such as picking up your gym bag, conveniently placed by your front door).
In other words, to decide what the smallest self-compliance hoop you need to jump through is, and commit to it, every time.
Here are a few other examples on how to minimise resistance with new habits:
- If you’re writing a novel, you open your writing software and write one sentence (regardless of its quality).
- If you’re learning how to meditate, you set a timer and meditate for one minute.
- If you’re improving your social skills, on your commute to or from work, you say “hello” to one stranger.
We tend to err on either taking action, or not, but by committing to meet a ridiculously small quota, it’s impossible to resist.
Eventually, you’ll notice, the more comfortable you feel with starting, the more you’ll increase your output (albeit sustainably) and the less you’ll need to rely on motivation to begin – your new habit becomes a reward in and of itself.
When you’re process-dependent and outcome independent, positive outcomes become a by-product of an efficient habit that’s being improved upon.
If you can just get under way with the first step in the habit sequence, then the rest will tend to follow, because once you’ve made a start, no matter how trivial, there’s always something drawing you on to the end.
It will niggle away in the back of your mind like a television cliff-hanger; your rationale becomes: “I’ve picked up my gym bag, I may as well travel to the gym and exercise now”.
Although the technique is simple, we often forget it because we get so wrapped up in thinking about the most difficult parts of our habits.
The sense of foreboding can be a big contributor to resistance, but by reducing what’s needed to begin, we can minimise it.
A Final Word
The Zeigarnik effect has one caveat: it doesn’t work so well when we’re not particularly motivated to do the habit or don’t expect to do it well.
This is true of habits in general: when they’re unattractive or impossible, we don’t feel motivated to do them.
But if we value the habit and think it’s possible, just taking a first step can be the difference between failure and success.
 Dobelli, R. (2013) The Art of Thinking Clearly, London: Hodder & Stoughton.
 Baumeister, R.F., Bushman, B.J., (2008) Social Psychology and Human Nature, United States: Thompson Wadsworth.
 McGraw, K. O., Fiala, J. (1982) ‘Undermining the Zeigarnik Effect: Another Hidden Cost of Reward’, Journal of Personality, 50(1), pp. 58-66.
 Babauta, L. (2013) The Four Habits that Form Habits, Available at: http://zenhabits.net/habitses/ (Accessed: 9th September 2014).