Here's a research result that will be sure to shake up the academic community--people with bigger brains tend to be smarter than people with smaller brains.

While I guess there's some utility to quantifying the effect, what person with a reasonably sized brain would have thought otherwise? The effect may not be linear with brain volume, but it's almost mathematically provable that there would have to be a positive correlation. Does anyone imagine that a brain the size of a walnut could be as smart as one the average size of a human brain? To argue otherwise seems as spurious as the stubborn insistence by some (such as the late Stephen J. Gould) that there's no relationship whatsoever between "race" and IQ--it has to be driven more by political correctness than by logic.

> The effect may not be linear with brain volume, but it's almost mathematically provable that there would
> have to be a positive correlation. Does anyone imagine that a brain the size of a walnut could be as
> smart as one the average size of a human brain?

You're assuming a smooth function, which might be correct but doesn't have to be.

If you look at microprocessors, you will see better performance with increasing chip size, but if you made the chip really big, that would start to break down. There might be similar limits on biological computers.

What would happen if you took an average human brain and scaled it up? Well, you'd have more neurons to work with, but also longer propagation delays from one part of the brain to another, as well as engineering problems like maintaining blood supply and cooling. Without empirical data, or knowing a lot more about the operation of the brain than we do, I don't think you could say which way performance would go.

But then, I have a size 7 hat size, so what do I know? :-)

I suspect using simple brain volume may be too simplistic. By that view whales should be really clever.

I suspect you will have to look at the number of neurons and the number of connections, plus neuron switching and connection speed. But heck what the hell do I know?

Supposedly there are also people with hydrocephalus whose ventricles take up 90% of their skull, squashing their brains, yet are apparently of normal intelligence.

Somewhere I read that parrots are more intelligent than they should be, given their small brains.

Supposedly their neurons are more densely packed than in other vertebrates, enabling them to achieve their feats (memorizing and mimicking human speech).

Phrenology returns.

Let's give it the respect it deserves.

As I understand it, surface area is good. That's why you see all those folds in a brain. It increases the surface area. I don't know why this is considered good, but a bigger brain (all else being equal) would have more surface area, though it's not a linear relation. There are animals with much larger brains, for example, elephants and whales.

Rand, I think you're wrong about Gould. Read "The Mismeasure of Man", if you have not yet. His main point is not that "there is no relationship between race and IQ" - I don't think he expresses an opinion on that - but rather that this is an area in which almost all previous research proceeded from (predetermined) results to (manipulated) evidence - in other words, it was junk science.

Is there a relationship between race and IQ? I don't know, and neither do you, because there has been _no_ real scientific study of that, and there couldn't be, given that the concept of IQ is not scientific (beyond simply "whatever it is that a particular IQ test measures"), and neither is the concept of race. Gould's primary point however is not about IQs but about how science (or perhaps scientists) can fail in some cases, and how much the results are really determined by prejudices rather than facts.

Would have to be a positive correlation? Hell no, compare a PDP-11 with a modern PalmPilot. You might almost argue there would have to be an inverse correlation (shorter signal paths). Speaking as someone who has done graduate-level work in neurophysiology: we are so far from any understanding of the physical substrate of consciousness (let alone intelligence) that it is simply absurd to make any a priori argument.

P.S. It is very possible that some groups of people with a common heredity (or common culture, or diet, or chemical composition of drinking water or whatever) will score consistently higher or lower on a particular test. That is essentially meaningless, however, since it is (a) highly dependent on the particular test (b) the variation within a group is an order of magnitude greater than the supposed difference between groups and (c) the supposed causal variables are not readily quantifiable, and even then they tend to correlate with each other (e.g. heredity and culture).

Wasn't Einstein’s Brain 20% smaller than average? But had 200% more neuron to Neuron connections.