But underneath it all, say the evolutionary psychologists, we still have stone age minds in modern skulls. There's an endless of things that we do that make no sense from a narrow biological point of view. So, strip away the shoulder pads and the mobile phones, the designer suits and the brand-name sportswear, and underneath there's a caveperson cast adrift in a modern world. It's not a new idea of course, but evolutionary psychologists have a new explanation for why it should be so. For all we know, there could have been evolution since then but 10,000 is a drop in the bucket compared to the 68-million years since we separated from chimpanzees.
Evolutionary change is very slow.
If things were happening very quickly then what this would mean is that different modern human populations would be genetically very different from each other in important respects. And there's all sorts of evidence that that's not true, that when you actually go out and look at the genes that are present in one human population versus another human population, there are some minor differences, but nobody's found a large set of genes which were present in one race or one population which are absent in other human races or other human populations. We all are inter-fertile, we all look as if we have the same basic equipment. That wouldn't be the case if natural selection was operating very quickly. And since we know very few genetic changes have taken place since the rise of agriculture in the human species, we know that basically our modern human brains are stone age minds inside modern human societies.