On Tue, 4 Apr 2006, Joan Warmbold went:
BTW, I'm continually baffled at why, when differences are discovered between adults' brains structure and chemistry, the assumption is almost always that this difference existed from birth? As we all know, literally thousands of studies have revealed the crucial role of early experience in sculpting our brain--i.e., brain plasticity. So why isn't this discussed in these publications as a viable alternative hypothesis?
That's a really important point, and fortunately, it does get some attention from the better writers on the subject. I'm pretty sure Simon LeVay discusses it in _The Sexual Brain_. And here's Marc Breedlove, driving the point home: "When does a sex difference in the CC appear? Despite an early report that the sex difference in splenial width (favoring females) was present in fetal brains (de Lacoste et al 1986), there have been no replications and several failures to detect a sex difference in children (Bell & Variend 1985, Clarke et al 1989, Allen et al 1991), albeit with small sample sizes. Thus there is little reason to believe the dimorphism in the CC is congenital." --David Epstein [EMAIL PROTECTED] Reference: Breedlove SM. Sexual differentiation of the human nervous system. Annual Review of Psychology 4. 45:389-418, 1994. --- You are currently subscribed to tips as: [email protected] To unsubscribe send a blank email to [EMAIL PROTECTED]
