This talk was given at a local TEDx event, produced independently of the TED Conferences. Why do human beings seem to come in two distinct political colors? Hannah Holmes outlines a hypothesis based on our history of as a tribal animal without access to penicillin or match.com. Ms. Holmes draws from new research from fields of psychology, psychiatry, and political science to support her hypothesis.

Hannah Holmes is the author of four books ranging in subjects as varied as a natural history of dust to the evolution of the diverse spectrum of human personalities. Her accessible and humorous science writing is widely translated and frequently used in classrooms. A Maine native, Ms. Holmes began a freelance writing career while at the University of Southern Maine. After working
as a magazine editor in New York, she developed a freelance specialty in eco-
travel and science. An early contributor to The Discovery Channel Online, she
participated in a number of pioneering media adventures, including "web TV"

broadcasting, themed blogging, and live blogging from a series of remote and
inconveniently located scientific expeditions. Her writing clients have included National Geographic, Discover, and The New York Times Magazine. Recently, Ms. Holmes has made a profession of her long-held fascination with human shelter, included assisting a wildlife rehabilitator who sought in-home accommodations for a ten-foot alligator.

About TEDx, x = independently organized event In the spirit of ideas worth spreading, TEDx is a program of local, self-organized events that bring people together to share a TED-like experience. At a TEDx event, TEDTalks video and live speakers combine to spark deep discussion and connection in a small group. These local, self-organized events are branded TEDx, where x = independently organized TED event. The TED Conference provides general guidance for the TEDx program, but individual TEDx events are self-organized.* (*Subject to certain rules and regulations)