Psychologist and best-selling author Shawn Achor has made a career studying the science of happiness.

"Scientifically, happiness is a choice," Achor says. He explains that research has shown you can rewire your brain to make yourself happy by practising simple happiness exercises every day for three weeks.

Texas-born Achor's books include The Happiness Advantage and Before Happiness.

Achor says in just 21 days, the exercises can transform a pessimist into an optimist. 

Shawn Achor

Shawn Achor, author of The Happiness Advantage, says you can rewire your brain to make yourself happy by practising simple happiness exercises. (CBC)

And within 30 days, those habits change the neuropathways of our brains and turn us into lifelong optimists.

These six daily happiness exercises are proven to make anyone, from a 4-year old to an 84-year old, happy, or simply happier, Achor says.

  1. Gratitude Exercises. Write down three things you're grateful for that occurred over the last 24 hours. They don't have to be profound. It could be a really good cup of coffee or the warmth of a sunny day. 
  2. The Doubler. Take one positive experience from the past 24 hours and spend two minutes writing down every detail about that experience. As you remember it, your brain labels it as meaningful and deepens the imprint.
  3. The Fun Fifteen. Do 15 minutes of a fun cardio activity, like gardening or walking the dog, every day. The effects of daily cardio can be as effective as taking an antidepressant.
  4. Meditation. Every day take two minutes to stop whatever you're doing and concentrate on breathing. Even a short mindful break can result in a calmer, happier you.
  5. Conscious act of kindness. At the start of every day, send a short email or text praising someone you know. Our brains become addicted to feeling good by making others feel good.
  6. Deepen Social Connections. Spend time with family and friends. Our social connections are one of the best predictors for success and health, and even life expectancy.

VIDEO:  5 happiness tips from Shawn Achor