Thirty years ago, human happiness seemed like a pretty unserious subject for scientific study. These days positive psychology, as happiness research is known, is de rigeur. Oscar-nominated filmmaker Roko Belic ("Genghis Blues") explores the science of contentment in his latest doc, "Happy." Belic traveled to five continents, talking to researchers, comparing the state of satisfaction in various countries and finding some very jolly people. Does happiness depend on our material conditions? Just how much control do we have over our own sense of well-being? And whence the intellectual prejudice that happiness lacks gravitas?

Of the many fields in which gender equality has been a long time coming, comedy might not seem as important as, say, high political office or corporate captaincy or astronaut-hood. But it would be a mistake to underestimate the power and centrality of humor in modern-day America. The fact that comedy – especially stand-up – was until recently considered mostly a guy's game, and the speed with which funny women have closed the gap in the last couple of decades is worth pondering. Why the disparity in the first place? What changed, and why does it matter? I spoke to Yael Kohen, author of the recent oral history "We Killed: The Rise of Women in American Comedy."

A tune-filled celebration and cerebration with neuroscientist, musician and record producer Daniel Levitin, author of "This is Your Brain on Music." Originally broadcast in 2007.

Geoff Nunberg says that when he told people he was writing an entire book about "asshole," both the word and the cultural condition, they laughed. But he soldiered on and produced a revelatory work in the tradition of the great exploratory essayists. Tracing the history of one of our favorite put-downs, "Ascent of the A-Word: Assholism--the First Sixty Years" maps some of the most important currents in American society over the last century.

Nate Silver isn't the only forecaster to project the results of last Tuesday's presidential election with preternatural accuracy. Sam Wang of the Princeton Election Consortium and Drew Linzer of Votamatic both hit the bullseye, too, and they explained to me why it's not really so preternatural after all (hint: statistical science works). We talked about their methods, why so many pundits and political partisans missed the boat, and whether it's bedtime for bloviators.

The last time I had journalist and author Don Lattin on the show, we discussed his book "The Harvard Psychedelic Club," about Timothy Leary and Co. This time, we talked about a previous generation of consciousness raisers. Don's new book, "Distilled Spirits: Getting Drunk, Then Sober with a Famous Writer, A Forgotten Philosopher and a Hopeless Drunk," tells the intersecting stories of Aldous Huxley, spiritual voyager and author of "The Doors of Perception"; his compatriate Gerald Heard, philosophical mystic and early acid head; and Bill Wilson, friend of Heard and founder of Alcoholics Anonymous. The book is also a memoir of Don's own psychedelic experiences, his drug and alcohol addiction and AA-assisted recovery.

Science writer David Quammen explores one result of our "infernal, aboriginal connectedness" to the animal world: a lot of diseases spilling over from other species to us. Examples include SARS, HIV, avian flu, Lyme disease and Ebola. Quammen says the phenomenon is on the increase, thanks to human actions. We discussed the science behind "zoonotic" diseases and David's globe-trotting research for his new book "Spillover: Animal Infections and the Next Human Pandemic."

Two new movies pay tribute to musical instruments and/or traditions that haven't always gotten their due in mainstream USA. In part one, Tad Nakamura, director of "Jake Shimabukuro: Life on Four Strings." It's a moving portrait of the musician who's taken the yukulele—-sometimes wrongly dissed as a novelty instrument—-to virtuosic heights. In part two, Tom Gunderson director of "Mariachi Gringo," the tale of a young man from the midwest who falls in love with Mexico and devotes himself to mariachi music. Lead actor Shawn Ashmore devoted himself to the music too, going to school on vihuela. The film also includes Mexican diva Lila Downs.

Martin Rees isn't just one of the world's most respected cosmologists (and Britain's Astronomer Royal), who's contributed to some of the field's biggest advances over the last four decades. He's also an ecumenical thinker with a broad view of the sciences and their limits, our historical moment and the long-range prospects for earth and its inhabitants. We talked about cosmology past and present, the politics of science in the US and Europe, science vs. religion, climate change and the human (or post-human) future.

Do I have to write a description of this interview? Can I simply say, “just listen”? Since his debut album came out in 2010, jazz/soul singer Gregory Porter has quickly won a passionate following around the world. It's easy to see why: there's so much depth and warmth and poetry in his vocals and compositions. And as our conversation made clear, those qualities come straight from the man himself. So just listen, and don't miss the end.