16. Alain de Botton, Philosopher selected John Armstrong, Philosopher

John is a writer and philosopher. He is the author of ‘In Search of Civilisation: Remaking a Tarnished Idea’. He is a very bold thinker, and argues that capitalism has gone wrong not because there aren't enough regulations on businesses but because there isn't enough education of consumers. In his opinion, the task is not to ban McDonald's, but to educate our desires so that we might "freely" consider alternatives.

17. Juan Enriquez, Life scientist selected Ed Boyden, Optogeneticist

Ed’s research at MIT founded the field of optogenetics. Now we can observe how a brain reacts as it hears, feels, sees, smells, remembers, and loves. But possibly more interesting, scary and weird is that he's developed ways to promote or suppress memories and feelings by using fibre-optic light.

18. Dan Ariely, Behavioral economist selected Michael Norton, Social scientist

“Mike Norton is one of the most creative social scientists I know. By asking unusual questions about the relationship between wealth and happiness he comes up with very interesting findings, observations and conclusions,” said Dan. There's also significant amount of literature on the theory that, as people become richer, they don't necessarily become happier. Norton instead asked whether people know how to use money to buy happiness.

19. Esra'a Al Shafei, Internet activist, founder and director of MideastYouth.com selected Yana Buhrer Tavanier, Human-rights activist

“My choice is a Bulgarian activist and investigative journalist working to expose the inhumane treatment of children and adults with disabilities and mental illness in the Balkans. She's also a prominent member of the Bulgarian LGBT-rights movement but her influence expands beyond Bulgaria. We met at TED.

20. Matt Ridley, Writer selected Reuben Abraham, Economist

Matt said “Reuben's probably the smartest, coolest and funniest economist I know, with an unrivalled and unsentimental understanding of the economic development of Asia and indeed the world.