DaveC426913 said:
A physical and quantifiable way of measuring mental sophistication is the number of neural connections. As we learn more (and improve more) in virtually any cognitive way, the number of neural connections increases. This creation of connections that did not exist before is qualitatively different than simply rearranging existing parts.
I might expect a gaussian or a bell curve or a maxwell-Boltzmann distribution of "mental sophistication" as a function of synaptic count, or SOME kind of function with a peak. Once you over-express connectivity, you would get too much synchronization, not enough isolation. So I think a hierarchical organization of the network topology will probably be washed away with too many neural connections, and the topology is important to keeping an organism at homeostasis.
In most cases in nature, we probably wouldn't see over-connectivity globally, but I wonder if some regions the brain have diseases associated with too many synapses locally (or shouldn't we include gap junctions, too?)
There's also the issue now of astrocytes, which is a part of the new concept of the tripartite synapse. Astrocyte translation regulates a lot of subcellular trafficking at the synapse that's associated with plasticity.
Though your post does remind me of a podcast I heard by Judith Lauter:
http://www.zebrabrain.com/book.htm
she mentions low-T vs. high-T brains, and I think the stereotype I came away from it with was basically that jocks who only play football were exposed to high levels of testosterone in the womb, and artsy fartsy science kids who like to dabble in all kinds of different things are associated with low testosterone exposure in the womb.
I identified with her characterization of low-T.