In his 2014 TED Talk, behaviour scientist BJ Hogg shares the tiny habit that he says is the most powerful and effective at changing behaviour, based on his research at Stanford University's Persuasive Tech Lab:

In the morning, when you wake up and put your feet on the floor, say out loud: "It's going to be a great day."

In addition to making you feel good, says Hogg, this tiny habit can lead to other positive actions right after and through the rest of the morning, such as working out.

What makes this habit so easy to adopt and stick to? Hogg explains that it happens in the morning, it's really easy to do, it's done in a designated spot, and it makes you feel good.

In his research, Hogg found that, for people who chose this habit to work on, it became automatic—much more so than another popular habit, namely, identifying one thing you're grateful for when your head hits the pillow at night.

Hogg suggests several variations on the morning statement:

And on days when he knows he will be facing a challenge, he says:

He finds that, even on his toughest days, he gets to the end of the day and sees that it was, in fact, a great day.

Hogg notes that when teaching people how to bring a habit into their lives, he follows this principle: "plant a good seed in the right spot and it will grow without further coaxing." The good seed is a small behaviour that you want to adopt. The right spot is the place in your day that the new habit fits. "If you get that combination right, it will grow, it will blossom on its own," says Hogg.

I share this tiny habit today in honour of World Mental Health Day, which—according to the World Health Organization—aims to raise awareness of mental health issues and to mobilize efforts in support of mental health.

In a world where so much is out of our control, I wanted to focus on something that is within our control: our ability to choose our outlook. Some days are easier than others to say, "It's going to be a great day." But even on days when we face an unpleasant task, we can probably say, "Today is going to bring good things."

On my first day of chemotherapy, for example, the "good things" included my husband's support, kind and professional nurses and other healthcare professionals, treatment that would help rid my body of cancer, medications to lessen the side effects of the chemotherapy, a family that welcomed me home, and a care package from my sister, niece and mom.

Saying "it's going to be a great day" may not feel genuine every day, but it will inspire us to look for the good that does arise, such as time spent with loved ones, a chance meeting with someone we haven't seen in years, and a note of appreciation from a friend.