The Dragons of Eden: Speculations on the Evolution of Human Intelligence

Dr. Carl Sagan takes us on a great reading adventure, offering his vivid and startling insight into the brain of man and beast, the origin of human intelligence, the function of our most haunting legends--and their amazing links to recent discoveries.

The Dragons of Eden: Speculations on the Evolution of Human Intelligence is a Pulitzer Prize-winning 1977 book by Carl Sagan. In it, Sagan combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on how human intelligence may have evolved.

Sagan discusses the search for a quantitative means of measuring intelligence. He argues that the brain to body mass ratio is an extremely good correlative indicator for intelligence, with humans having the highest ratio and dolphins the second highest, though he views the trend as breaking down at smaller scales, with some small animals (ants in particular) placing disproportionally high on the list. Other topics mentioned include the evolution of the brain (with emphasis on the function of the neocortex in humans), the evolutionary purpose of sleep and dreams, demonstration of sign language abilities by chimps and the purpose of mankind's innate fears and myths. The title "The Dragons of Eden" is borrowed from the notion that man's early struggle for survival in the face of predators, and in particular a fear of reptiles, may have led to cultural beliefs and myths about dragons.

In 2002, John Skoyles and Dorion Sagan published a followup to The Dragons of Eden entitled Up from Dragons.

"A history of the human brain from the big bang, fifteen billion years ago, to the day before yesterday...It's a delight."

- THE NEW YORK TIMES