We can increase the FLOPs of a CPU by reducing resistance, increasing the size of cache, reducing distance between I/O devices.
Might IQ be a measure of the aggregate of the benefit of equivalent measures of neurons?
For example, we know that MS patients have autoimmune diseases that attack the myelin sheath on neurons which slows their neuronal processing speed. Perhaps higher IQ people might have more Schwann cells to speed neuronal transmission more than lower IQ people.
Maybe the diameter of neurons or the width of the gap between the synapses. Or the sheer number of neurons and synapses might be different.
IQ could be an indirect measurement through test taking, that approximates a combined measure of all the physical properties of neurons and their arrangements that contribute to higher intelligence.
That seems a reasonable approximation from my perspective as a layman. A couple of things (that I am sadly lacking sources for right now) that might suggest this interpretation include:
- there is a meaningful (albeit small) correlation between IQ and reaction times
- people with higher IQs show lower brain activation when performing cognitive tasks compared to people with lower IQs. That is, their brain has to do less work to perform the same task.
Sure. For example, we know that IQ is correlated quite substantially (though far from perfectly) with the brain volume within all populations for which such measurement was made. There is a huge confounded here however, which is women having significantly smaller brains than men, but not scoring any worse on IQ tests, or being any less intelligent than men, even though smaller brained men tend to be less intelligent than larger brained men, and also smaller brained women tend to be less intelligent than larger brained women. It is thought that this apparent disparity is can be explained by increased “density” of neurons in some sections of women’s brains, compared to the same sections of men’s brains. I’m quite sure you can find references for it in Jensen’s “The g factor”.
The density difference is due to physical support for impact resistance. The jawline difference also relates to impact resistance. It seems that evolution accounts for men getting punched more often.
That being said, IQ is highly predictive one's ability to perform a broad range of cognitive tasks (along with many other important life outcomes).