On this week's show Roisin meets Tal Ben-Shahar to talk about that most elusive of states: happiness. Along with his colleague Daniel Philbin Bowman, Tal tells Roisin about his lifelong investigation into the attainment of a positive mental state, and the simple things that people can do to be more content.

Tal Ben-Shahar is a Harvard lecturer in positive psychology, an author of several books on happiness and the founder of Potentilife, a 9-month leadership development program.