@NC While nurture does play a significant role, genetics also influences brain development. Neandertals were after all a different species of human, and just as the brain of bonobo is different from that of a gorilla because of genetics, so to would the brain of a homo sapien be different from that of a Neanderthal. We can see this is skull impressions of Neanderthals, which shows that they tended to have a larger occipital lobe than us, and a small prefrontal cortex.
as for the tendency for European features, you must remember that Neanderthals lived in colder environments where sunlight was weaker. Lighter skin and hair was advantageous because it allowed for more vitamin D be produced by the skin when it was exposed to sunlight. Someone with very dark skin, especially a pregnant female and her baby, would be at a disadvantage in such an environment, especially since food was not as easy to come by as it is has been in the modern world.
While nurture does play a significant role, genetics also influences brain development. Neandertals were after all a different species of human, and just as the brain of bonobo is different from that of a gorilla because of genetics, so to would the brain of a homo sapien be different from that of a Neanderthal. We can see this is skull impressions of Neanderthals, which shows that they tended to have a larger occipital lobe than us, and a small prefrontal cortex.
as for the tendency for European features, you must remember that Neanderthals lived in colder environments where sunlight was weaker. Lighter skin and hair was advantageous because it allowed for more vitamin D be produced by the skin when it was exposed to sunlight. Someone with very dark skin, especially a pregnant female and her baby, would be at a disadvantage in such an environment, especially since food was not as easy to come by as it is has been in the modern world.