Arianna Huffington talks to Anne McElvoy about measuring success using The Third Metric. Richard Hytner and Kerrie Fleming look at stress in business and the nature of leadership. Zia Haider Rahman on his debut novel In the Light of What We Know which contains elements of his own Bangladeshi background, a scholarship to Oxford and time spent as an investment banker on Wall Street. Plus Anne pays tribute to the late Maya Angelou's influence and humour.