> My gut feeling is an unhealthy brain would lead to less
> intelligence, BUT what of epileptics (unhealthy brains, no?) such as
> Dostoyevsky? Are they counterexamples? Or could it be, if your (Gray's?)
> hunch is correct that Dostoyevsky, etc. would have been even smarter had
> they not had epilepsy? Or perhaps epilepsy might be different in this
> respect -- i.e., it might not have much to do with intelligence whereas
> other aspects of brain health might.
It seems likely that some aspects of intelligence will prove to be very complicated, and that there are trade-offs in some sets of genes vs. other sets of genes. For example, there is a clear link between schizophrenia and creativity; there was a study done in Iceland (Greenland?) where they compared families where there was at least one schizophrenic in the family to those without any family history of schizophrenia. The families which had a history of schizophrenia were twice as likely to have a member of the family listed in the Icelandic (Greenlandic?) version of "Who's Who."
It's believed that schizophrenia may be triggered if the mother catches one of several viruses during pregnancy, but only if the child has the genes that make him vulnerable. But perhaps if the mother does not get a virus, the child grows up to be smarter or more creative as a result of having the schizophrenia gene.