A new form of psychology - positive psychology - suggests we can think ourselves happy and actually rewire our brains to be more optimistic.
We are told we all have a set range of happiness. Now positive psychologists say we can make ourselves 10-15% happier permanently - if we work at it.
And they are keen to try it out on a whole nation.
click here to see where to watch or .
Ready to Watch The Happiness Formula, Season 1, Episode 2?