Jonathan Haidt studies how -- and why -- we evolved to be moral and political creatures.

TED Fellow Jess Kutch is the cofounder of Coworker.org, a nonprofit that helps people join together to improve their jobs and workplaces.

Jarrell Daniels brings policy makers together with community members to improve social challenges, particularly among youth.

Dr. Leana Wen is Baltimore City's Health Commissioner.

Srdja Popovic was a founder and leader of the student movement that brought down the Milosovic regime. Now, he helps other nonviolent movements learn and grow.

Katherine Gehl is a business leader turned political innovator.

Fareed Zakaria hosts "Fareed Zakaria GPS" for CNN Worldwide and is a columnist for "The Washington Post," a contributing editor for "The Atlantic" and a bestselling author.

Sophal Ear leads research on post-conflict countries -- looking at the effectiveness of foreign aid and the challenge of development in places like his native land, Cambodia.

Karima Bennoune's new book introduces the world to people who speak out against fundamentalist terrorism.

Philippa Neave is senior advisor on the UN's Lexicon of Electoral Terminology.

Anti-censorship activist

Human rights activist

Post-conflict reconstruction educator

Investigative journalist

Conflict and security researcher

Architect