New evidence reveals the truth behind the notorious Roman emperor Caligula.

Why do we hate? Humans are capable of love and cooperation --so why do we treat each other with cruelty and violence? Evolutionary anthropologist Brian Hare searches for the origins of hate in our distant past, and in our contemporary environment.

Why do we divide the world into 'us' and 'them'? Cognitive scientist Laurie Santos examines tribalism, asking why love for our group can make us hate other groups --in politics, sports, even warfare --and how tribal thinking shapes our perceptions.

If we all have the capacity to hate, what does it take to awaken our worst tendencies? Journalist Jelani Cobb investigates how "hate tools" like propaganda, dehumanization, the internet, symbols, and more can incite, amplify and spread hatred.

What drives us to embrace hateful ideas? Extremism expertSasha Havlicek explores the complicated factors that draw people toward ideologies that fuel hate and violence from white nationalism to Islamic terrorism or toward deradicalization.

What makes us take part in the worst extremes --genocide and crimes against humanity? Criminal lawyer Patricia Viseur Sellers investigates the role of perpetrators, from leaders to followers, as well as those who resist the power of hate.

How can we resist succumbing to our worst impulses and awaken the our angels? Neuroscientist Emile Bruneau explores how we can use our capacity for critical thinking, our brain plasticity, and other strategies to help combat hate.

Special 2-Hour event hosted by Tamron Hall featuring the "Why We Hate" documentary and a roundtable conversation about the documentary and the ongoing events surrounding George Floyd's death.

Influenza delves into the history and impact of this constantly evolving virus, which is often tragically underestimated as merely a cousin to the common cold. The episode explores the ongoing threat it poses & the complex science behind it.

Smallpox is one of the deadliest killers on the planet, and though it has been eradicated, it remains a major bioterror threat.

Ebola is one of the world's most lethal viruses, and a perfect storm in 2014 caused the deadliest breakout in history.

Discover how aluminum foil, snowboards, contact lenses and bread are made.

Discover how compact discs, mozzarella cheese and pantyhose are made.

Discover how toothpicks, acrylic bathtubs, helicopters and beer are made.

Discover how hearing aids, 3D puzzles, rubber mats and toilets are made.

Discover how copy paper, jeans, computers and plate glass are made.