I shouldn't have said compressed, as it implies something larger which has been squashed, when in fact it never developed in the first place. And I don't think one can reduce it to a this size brain versus that. It doesn't take into account quality or evolution (change over time). There are plenty of examples of ancient creatures which still inhabit the earth along with modern types, horseshoe crabs for example, or lampreys.
As far as I know, brain size is related to body size. And you're right, size implies nothing, as neanderthals had bigger brains, but no one would consider them as the sharpest tool in the shed
Neanderthals had severe prognathism. The brain was larger, but flatter across the skull, with the frontal and parietal lobes undeveloped. It's structure would have been more primitive, compared to sophisticated modern brains.
Association does not imply causation. Likewise, larger brains are associated with smaller or absent tails, both in primates and some other animals, dinosaurs, aforementioned in the first post, I believe. One could also make up some developmental idea for that, like that many animals can only grow bigger brains by sparing the resources that would have otherwise being used in developing the tail; but by itself it's just free-association of facts. I believe that acromegaly and most evidently hydrocephaly count as evidence against this jaw-muscles-compresses-brain-during development idea. The first includes an enlargement of the jaw, perhaps accompanied by enlargement by the cranial vault; the second is essentially enormous enlargement of the head, not requiring smaller jaws than normal. Please Register or Log in to view the hidden image! Acromegaly Please Register or Log in to view the hidden image! hydrocephaly Furthermore, males have larger brains than women (proportionally, not just because men are usually larger), despite having also larger and more muscular jaws. And last, but not least, since around the eve of the genus Homo the lineage has a defective version of the gene that is responsible for the muscular jaws of the other great apes and australopithecines. So, even if this event did make room for a bigger braincase, apparently it allows for all the variation from Homo erectus to Homo sapiens (which sometimes overlap, Anatole France being a famous example). From this perspective, the little differences on the jaws of different human populations (it does not vary only between white/yellow/black racial lines, but also within) and sexes does not seem to impose a developmental constraint for the braincase. I think that even though there might be some truth to the notion, in this long-term evolutionary perspective, these examples indicate that this hypothetical mechanism is not a restraint in the variation of those jaw/braincase differences at the level of present/recent human populations and sexes. ... I think that it's funny that, if the history had taken a different turn, and black and white people had taken the inverse socio-economical roles, we'd see much of the same sort of reasoning of "scientific racism"; they'd point that white people probably are economically disadvantaged and less intelligent as a result of some evolutionary reversals, as they've lost many human/black traits: the skin, which is often pale in our closest relatives; thick lips, which are almost nonexistent on chimps; nappy hair, which is almost an exclusively human trait; body hairlessness, which again, separates us from chimps; how possibly there's some link between more melanin and more neuromelanin and better brain function, and so on. Possibly some arguments like these are already used by black supremacists anyway.
1) I see a fist and a shadow where MLK's protruding jaw may or may not be. 2) this is the most roundabout way of being racist I have seen in a long time 3) MLK despite his alleged jaw issue was a talented leader, speaker and writer. Whatever the shape of his brain, it worked well, until someone from a race with a 'better' jaw shot him.
