Richard E. Leakey

The challenge for individuals in primate societies is to be able to predict the behavior of others. One way would be for individuals to have a huge mental bank in their brains, which stored every possible action of their fellow troop members and their own appropriate actions.

The neurobiologist Harry Jerison has made a long study of the trajectory of brain evolution since the advent of life on dry land. ...the origin of new faunal groups is usually accompanied by a jump in the relative size of the brain, known as encephalization. ...the first archaic mammals... were equipped with brains four to five times bigger than the average reptilian brain... primates are twice as encephalized as the average mammal. Within primates, the apes... are some twice the average size. And humans are three times as encephalized as the average ape.

When our ancestors discovered the trick of consistently producing sharp stone flakes, it constituted a major breakthrough in human prehistory. ...The modest flake... is a highly effective implement for cutting through all but the toughest of hides... the humans who made and used these simple stone flakes thereby availed themselves of a new energy source—animal protein.

In order to be able to deceive intentionally, an animal must have a sense of how its actions appear to another individual. Such an ability requires self-awareness.

Next to the discovery of the Turkana boy, the visit to Lascaux ranks as one of the great moments of my life.

When a San Shaman goes into a trance, he harnesses that power, becomes part of the world beyond, becomes invisible to the singers and dancers around him, and draws images on the rock face. Ask the San who drew the images, and they say the spirits. And the rock face is more than a surface for the paint; it is the boundary of this world and the world beyond. ...part of the meaning of it all, and the rock shelter itself assumes a special status, a place of veneration.

Of the range of images in Upper Paleolithic art, the most arresting are the therianthropes. There are not many... but they seize the imagination. The most famous is the so-called sorcerer... In a manner unusual for Upper Paleolithic images, the sorcerer is staring directly out of the wall, a full-face stare that transfixes the spectator.

This tendency to anthropomorphize flows naturally from the context in which consciousness evolved. Consciousness is a social tool for understanding the behavior of others by modelling it on one's own feelings.

The French archeologists Iégor Reznikoff and Michael Dauvois conducted detailed surveys of three decorated caves in the Ariège region of southwest France. ...they moved slowly through the caves, stopping repeatedly to test the resonance of each section... spanning three octaves... those areas with highest resonance were also those most likely to harbor a painting or engraving. ...a fascinating discovery that... Chris Scarre commented at the time, draws "new attention to the likely importance of music and singing in the rituals of our early ancestors."

People who pass from stage two hallucination to stage three often experience a sensation of a vortex or rotating tunnel around them, and soon have hallucinations filled with iconic images, not just signs. ...It is here that "monsters" appear, part human, part beast, known as therianthropes.

The first era of the Upper Paleolithic, the Aurignacian, is notable for several reasons, one of which is the absence of painted caves. ...One of the most evocative pieces from this era, from the Abri Blanchard in southwestern France, is a flute. Music must have been an integral part of Upper Paleolithic life too.

Where Breuil has seen chaos—or at least, randomness—in wall art, Leroi-Gourhan sought and found order.