A new study argues that the dark sides of human nature, particularly the moral conflicts which erupt from betrayals of trust, were responsible for our dispersal around the globe 100,000 years ago.

Dr. Penny Spilkins, an archaeologist from the University of York, argues that during the Late Pleistocene there was a dramatic change in the rate and pattern of human dispersal. Until that time human migrations were the result of clear, practical factors, whether population increases or ecological and environmental changes.

Something changed to drastically accelerate the rate of dispersion however. Human populations spread with much greater speed, transcending the environmental obstacles that had hitherto restricted their movements to progress out of Africa and reach the furthest corners of the globe.