Jonathan Balcombe, an expert in animal behavior, describes the variety of animals that seem to demonstrate pleasure, and pleasure's theoretical origins in evolution. Balcombe is an animal behavior research scientist at the Physicians Committee for Responsible Medicine in Washington, D.C., and the author of Pleasurable Kingdom: Animals and the Nature of Feeling Good (Macmillan, 2006)

Speaker: Johnathon Balcombe

Date: April 24, 2006

Length: 58:13