Over his decades-long career as a political activist, Ralph Nader has helped expose some of the greatest misdeeds of large corporations. You may be familiar with the real-world changes his work sparked: the Clean Air Act, automobile safety laws, regulation of the tobacco industry and more. Tracing the arc of his time advocating for change, Nader...

The term Gross Domestic Product is often talked about as if it were “handed down from god on tablets of stone.” But this concept was invented by an economist in the 1930s. We need a more effective measurement tool to match 21st century needs, says Michael Green: the Social Progress Index. With charm and wit, he shows how this tool measures socie...

Does what you share online reveal more than you think? Discover what your personal data says about you with these insightful talks.

The Italian island of Sardinia has more than six times as many centenarians as the mainland and ten times as many as North America. Why? According to psychologist Susan Pinker, it's not a sunny disposition or a low-fat, gluten-free diet that keeps the islanders healthy -- it's their emphasis on close personal relationships and face-to-face inter...

Jon Ronson is a writer and documentary filmmaker who dips into every flavor of madness, extremism and obsession.

How smart can our machines make us? Tom Gruber, co-creator of Siri, wants to make "humanistic AI" that augments and collaborates with us instead of competing with (or replacing) us. He shares his vision for a future where AI helps us achieve superhuman performance in perception, creativity and cognitive function -- from turbocharging our design ...

Hilary Cottam wants to redesign the welfare state using the power of relationships.

Can global capital markets become catalysts for social change? According to investment expert Audrey Choi, individuals own almost half of all global capital, giving them (us!) the power to make a difference by investing in companies that champion social values and sustainability. "We have more opportunity today than ever before to make choices,"...

Stand-up comedian Negin Farsad counters Islamophobia in funny and clever ways.

Our environment changes faster than we can learn about it, Eddie Obeng says. How do we keep up?

Jamais Cascio follows the threads of civilization's intended (and unintended) consequences into an unpredictable future, bringing back glimpses of a green world wired beyond our wildest dreams.

Ellen Dunham-Jones takes an unblinking look at our underperforming suburbs -- and proposes plans for making them livable and sustainable.

Scott Galloway teaches brand strategy and digital marketing and the NYU Stern School of Business. He is the author of "The Four" and "The Algebra of Happiness," and cohost of the "Pivot" podcast.

Often called a social poet, C.K. Williams was fascinated by the characters of modern civilization and their interactions.

As the leader of Darpana, Mallika Sarabhai is a pioneer in using dance and the arts for social change.

Photojournalist James Nachtwey is considered by many to be the greatest war photographer of recent decades. He has covered conflicts and major social issues in more than 30 countries.

A human resources activist, Morgana Bailey wants to see the diversity of society reflected in the workplace, and employees of all walks of life feel comfortable being open about who they are.

What kinds of stories move us to act? To answer this question, creative technologist Heidi Boisvert is measuring how people's brains and bodies unconsciously respond to different media. She shows how she's using this data to determine the specific narrative ingredients that inspire empathy and justice -- and spark large-scale social change.

From Twitter to word of mouth, explore the ways ideas spread so quickly from person to person.

We are so preoccupied with happiness that the Declaration of Independence guarantees our right to pursue it. But are we doing it right? Historian Caroline Winterer argues that what the founding fathers meant was public happiness, the need for citizens to work collectively toward a robust democracy. "Only public happiness," she explains, "creates...

Many of us have a social media presence -- a virtual personality made up of status updates, tweets and connections, stored in the cloud. Adam Ostrow asks a big question: What happens to that personality after you've died? Could it ... live on?

Stefana Broadbent watches us while we communicate, work and go about our daily lives. She is one of a new class of ethnographers who study the way our social habits and relationships function and mutate in the digital age.

We need a more considered approach to using social media for social justice, says writer and activist Ione Wells. After she was the victim of an assault in London, Wells published a letter to her attacker in a student newspaper that went viral and sparked the #NotGuilty campaign against sexual violence and victim-blaming. In this moving talk, sh...

History is written by the victors, as the saying goes -- but what would it look like if it was written by everyone? Journalist and TED Fellow Mikhail Zygar is on a mission to show us with Project1917, a "social network for dead people" that posts the real diaries and letters of more than 3,000 people who lived during the Russian Revolution. By s...

TED Talks that make sense of this brave, new, virtual world.

Reporter Paul Lewis harnesses the power of mobile phones and social media -- innovations that are making every person a potential journalist.

Philip Zimbardo was the leader of the notorious 1971 Stanford Prison Experiment -- and an expert witness at Abu Ghraib. His book The Lucifer Effect explores the nature of evil; now, in his new work, he studies the nature of heroism.

Shaffi Mather is the founder of 1298 for Ambulance, Education Access for All, and co-promoter of Moksha-Yug Access.

David R. Dow has defended over 100 death row inmates in 20 years.

University student Ione Wells is the founder of the international #NotGuilty campaign against sexual violence and misdirected victim blaming.