"A popular misconception exists that the builders of the pyramids or the cave painters of prehistory were somehow less intelligent than we are. This simply isn't true - there is no evidence that the human brain has evolved at all in the last fifty thousand years at least. Modern people are merely benefiting from thousands of years of accumulated knowledge and experimentation, not from increased intellect. (...). This idea is part of a mistaken view of history best described as temporocentrism - the belief that our own time is the most important and represents a "pinnacle" of achievement. The temporocentric view is a hangover from nineteenth-century ideas of progress. (...). It is a kind of racism, in which our ancestors are looked down on simply because they lived in the past."
Quoted from: Ancient Inventions, Peter James and Nick Thorpe (Amazon link).