But what if raw human intelligence has not changed so much over the past 20,000 years? What if they were just as smart as modern man, only the benefit of thousands of generations of accumulated knowledge? We should not assume that we are fundamentally more intelligent than an individual born 20,000 years ago. We may have more knowledge and understanding of the world around us, but much of it was garnered from the experiences of others that went before us rather than the fruits of our own effort.” – Bruce Hood