In an earlier entry Fagan discusses the eyed needle as key technological advantage of the Cro-Magnons over the Neanderthals. In the passage quoted below, he discusses some other key differences between the two human species.
(p. 14) We know from their art that they looked at their world with more than practical eyes, through a lens of the intangible that changed constantly over the generations. It was this symbolism, these beliefs, as much as their technological innovations and layered clothing, that gave them the decisive advantage over their neighbors in the seesawlike climatic world of the late Ice Age. There were more of them living in larger groups than there were Neanderthals, too, so there were more intense social interactions, much greater food gathering activity from an early age, and an ongoing culture of innovation that came (p. 15) from a growing sophistication of language, advances in technology, and a greater life expectancy. In a world where all knowledge passed orally from one generation to the next, this enhanced cultural buffer between the moderns and the harsh climate provided an extra, albeit sometimes fragile, layer of protection during the intense cold of the so-called Last Glacial Maximum, from 21,500 to 18,000 years ago.
Fagan, Brian. Cro-Magnon: How the Ice Age Gave Birth to the First Modern Humans. New York: Bloomsbury Press, 2010.