All you need to do is keep the chain of change going, day by day, by day.

Aside from being one of the sharpest and most successful comedians of all time, Jerry Seinfeld is also streaks ahead when it comes to the science of behavioural reinforcement.

That is to say, he’s good at the habit of getting his habits to stick. His secret: chains. No, he doesn’t chain himself to his desk to write his famous observational jokes.

Rather, as he once told an interviewer, he uses a big yearly wall calendar, on which he marks every day with an X, as long as, on that day, he wrote. Then the next, then the next day, and so on, each successful writing day marked with an X.

If there was a day on which he didn’t write, the chain of Xes would be visibly broken. “Your only job,” says Jerry, “is not to break the chain.”

Applying this principle, which is also known as “streaks”, can be a simple yet powerful way to break into a new habit or break out of an old one.

Do you want to stop smoking? Do you want to write a novel? Do you want to learn a new language? Do you want to work out for a few minutes every day? Just get a calendar and a pen and keep the streak going.

The science behind this is called the COM-B Model of Behaviour Change, as theorised by researchers at University College London in 2011.

According to the model, the key factors required to change behaviour are: capability, meaning the psychological and physical ability to participate in an activity; Opportunity, meaning the external factors that make a behaviour possible; and Motivation, meaning the conscious and unconscious cognitive processes that direct and inspire behaviour.

Let’s say you want to start working out. You know you need to because it’s good for you. Also, you have some space at home where you can do your daily exercises.

That’s Capability. You can spare seven minutes a day to follow a recommended exercise programme. That’s Opportunity.

You picture yourself looking and feeling fit and healthy. That’s Motivation. It’s a cycle of change, and you keep it going by keeping it going.

But maybe you’re the sort of person who needs more than a calendar and a pen to keep an eye on your progress. The good news: there are apps to help you on your journey.

If you have an iPhone, visit the App Store and try Streaks, which allows you to track up to a dozen habits, with colourful icons and a bright interface to cheer you long.

You can set reminders and notifications, and while you’ll have to put in the work and stay the pace, the small reward of ticking off the tasks and beating your own streak will make it all worthwhile.

It’s best to start with a modest array of three to four habits that you want to break or acquire, to avoid putting too much pressure on yourself. (In Jerry Seinfeld’s case, all he wanted to do was sit down and write a few good jokes every day.)

If you’re an Android user, head for the Google Play Store and try HabitShare, which is also available for iOS. It’s a free app that also allows you to set daily and weekly goals for yourself, with the big difference being that you can choose to share your progress.

In that way, you motivate yourself by motivating others. And so, the cycle continues. Just don’t break the chain or stop the streak.

And if you do, just start all over again, and make it a habit!