brain sexual dimorphism [cont'd]

Daniel A. Foss (U17043@UICVM.BITNET)
Fri, 17 Feb 1995 21:06:33 CST

Gina Kolada, Times science writer, quoted Dr Sally E. Shaywitz, principal
investigator in the Magnetic Renonance Imaging study which found brain
sexual dimorphism in phonemic decoding in reading, to the effect that
there was no evolutionary survival or sexual advantage for the dimorphism,
considering that males and females performed the decoding task equally well.
Are all the parts of the latter suggestion equally valid? Might some survival
or sexual advantage have accrued to males or females at some time in the
evolutionary past, such as is not evident in the present? Why do males
outnumber females among the reading-disabled? Is there any possible relevance
to females outperforming males on standardized tests of language skills? To
comparative sociolinguistic studies showing that females tend to speak more
prestigious versions of local languages than do males? To the circumstance
that mothers typically transmit the phonemic structures of initially-acquired
languages to nursing infants and small children by age two? What cross-cultural
patterns, that is, do we already know about that might bear upon the
*evolution* of brain sexual dimorphism? Any ideas, even wild guesswork, sheer
supposition, etc, welcome. I'm confused.

Daniel A. Foss