Episode Details

The chili pepper evolved a chemical weapon to keep mammals away, and humans turned it into a global obsession. This episode explains how capsaicin tricks pain receptors into sensing a phantom burn, why it also protects seeds from Fusarium fungus, and why birds, which cannot feel the heat, are the plant's ideal seed dispersers.

We look at psychologist Paul Rozin's idea of constrained risk-taking, the plant's origins in Peru and Bolivia, and how Columbus's mislabeling of chilies as peppers kicked off a spread that reshaped world cuisines within a century. We also cover the Scoville scale, record-breaking peppers, medical and elephant-deterrent uses, and chilies grown aboard the International Space Station.

• How capsaicin hijacks nociceptors and why water does not put out the fire
• Why chili plants target mammals but not birds, and how they fight fungal attack
• How chilies spread from the Americas through Portuguese and Spanish trade networks
• From Wilbur Scoville's taste tests to HPLC and the 2.69 million SHU Pepper X
• Pain-relief creams, chili dung bombs for elephants and NASA's space-grown Hatch chilies