THEY DIDN'T HAVE FOREHEADS, THEY HAD EIGHTHEADS! (via Brian Boys):

What Happened to the Hominids Who May Have Been Smarter Than Us?: Two neuroscientists say that a now-extinct race of humans had big eyes, child-like faces, and an average intelligence of around 150, making them geniuses among Homo sapiens. (Gary Lynch and Richard Granger, December 28, 2009, Discover)

Boskops argue otherwise. They say that humans with big brains, and perhaps great intelligence, occupied a substantial piece of southern Africa in the not very distant past, and that they eventually gave way to smaller-brained, possibly less advanced Homo sapiens—that is, ourselves.

We have seen reports of Boskop brain size ranging from 1,650 to 1,900 cc. Let’s assume that an average Boskop brain was around 1,750 cc. What does this mean in terms of function? How would a person with such a brain differ from us? Our brains are roughly 25 percent larger than those of the late Homo erectus. We might say that the functional difference between us and them is about the same as between ourselves and Boskops.

Expanding the brain changes its internal proportions in highly predictable ways. From ape to human, the brain grows about fourfold, but most of that increase occurs in the cortex, not in more ancient structures. Moreover, even within the cortex, the areas that grow by far the most are the association areas, while cortical structures such as those controlling sensory and motor mechanisms stay unchanged.

Going from human to Boskop, these association zones are even more disproportionately expanded. Boskop’s brain size is about 30 percent larger than our own—that is, a 1,750-cc brain to our average of 1,350 cc. And that leads to an increase in the prefrontal cortex of a staggering 53 percent. If these principled relations among brain parts hold true, then Boskops would have had not only an impressively large brain but an inconceivably large prefrontal cortex.

The prefrontal cortex is closely linked to our highest cognitive functions. It makes sense out of the complex stream of events flowing into the brain; it places mental contents into appropriate sequences and hierarchies; and it plays a critical role in planning our future actions. Put simply, the prefrontal cortex is at the heart of our most flexible and forward-looking thoughts.

While your own prefrontal area might link a sequence of visual material to form an episodic memory, the Boskop may have added additional material from sounds, smells, and so on. Where your memory of a walk down a Parisian street may include the mental visual image of the street vendor, the bistro, and the charming little church, the Boskop may also have had the music coming from the bistro, the conversations from other strollers, and the peculiar window over the door of the church. Alas, if only the Boskop had had the chance to stroll a Parisian boulevard!

Expansion of the association regions is accompanied by corresponding increases in the thickness of those great bundles of axons, the cable pathways, linking the front and back of the cortex. These not only process inputs but, in our larger brains, organize inputs into episodes. The Boskops may have gone further still. Just as a quantitative increase from apes to humans may have generated our qualitatively different language abilities, possibly the jump from ourselves to Boskops generated new, qualitatively different mental capacities.

We internally activate many thoughts at once, but we can retrieve only one at a time. Could the Boskop brain have achieved the ability to retrieve one memory while effortlessly processing others in the background, a split-screen effect enabling far more power of attention?

Each of us balances the world that is actually out there against our mind’s own internally constructed version of it. Maintaining this balance is one of life’s daily challenges. We occasionally act on our imagined view of the world, sometimes thoroughly startling those around us. (“Why are you yelling at me? I wasn’t angry with you—you only thought I was.”) Our big brains give us such powers of extrapolation that we may extrapolate straight out of reality, into worlds that are possible but that never actually happened. Boskop’s greater brains and extended internal representations may have made it easier for them to accurately predict and interpret the world, to match their internal representations with real external events.

Perhaps, though, it also made the Boskops excessively internal and self-reflective. With their perhaps astonishing insights, they may have become a species of dreamers with an internal mental life literally beyond anything we can imagine.

Even if brain size accounts for just 10 to 20 percent of an IQ test score, it is possible to conjecture what kind of average scores would be made by a group of people with 30 percent larger brains. We can readily calculate that a population with a mean brain size of 1,750 cc would be expected to have an average IQ of 149.

This is a score that would be labeled at the genius level. And if there was normal variability among Boskops, as among the rest of us, then perhaps 15 to 20 percent of them would be expected to score over 180. In a classroom with 35 big-headed, baby-faced Boskop kids, you would likely encounter five or six with IQ scores at the upper range of what has ever been recorded in human history. The Boskops coexisted with our Homo sapiens forebears. Just as we see the ancient Homo erectus as a savage primitive, Boskop may have viewed us in somewhat the same way.

They died and we lived, and we can’t answer the question why. Why didn’t they outthink the smaller-brained hominids like ourselves and spread across the planet? Perhaps they didn’t want to.

So the supergeniusmen didn't believe in survival of their species?

Posted by Orrin Judd at January 7, 2010 6:28 AM