Path: utzoo!utgpu!watmath!iuvax!mailrus!tut.cis.ohio-state.edu!bloom-beacon!daemon From: geb@cadre.dsl.pitt.edu (Gordon E. Banks) Newsgroups: soc.feminism Subject: Re: sex/gender Message-ID: <13094@bloom-beacon.MIT.EDU> Date: 24 Jul 89 15:22:27 GMT References: <8907071844.AA10158@cattell.psych.upenn.edu> <10546@polya.Stanford.EDU> <12869@bloom-beacon.MIT.EDU> <10781@polya.Stanford.EDU> Sender: ambar@bloom-beacon.MIT.EDU Reply-To: geb@cadre.dsl.pitt.edu (Gordon E. Banks) Organization: Decision Systems Lab., Univ. of Pittsburgh, PA. Lines: 112 Approved: ambar@bloom-beacon.mit.edu In article <10781@polya.Stanford.EDU> elroy!ames!polya.stanford.edu!holstege (Mary Holstege) writes: >Oh? Where are all these studies? Seriously, I haven't seen a great many >studies that even look at these questions. How is `spatial ability' measured >in a vole, and why should we believe that it has anything to what is measured >by the various sorts of tests that are given to humans to measure the same >thing? I can't find the paper on the voles (I heard the author give a colloquium and have it somewhere). The usual method is learning mazes, which males are superior at. I am not sure what other methods were used. If you seriously want to read this work, I'll find the reference for you. He also talks about other mammals and the sexual territory stuff. >Why has the difference disappeared in Eskimos, if this is pervasive >throughout Mammalia? I don't know, and I am not familiar with the studies in the Eskimos. It isn't inconceivable that subpopulations might arise which lack the characteristic. Is this only one study, or have other workers verified it? >Ah. So a few studies on voles (using what measures?) justifies the >conclusion that among human beings (what? 100 million year separation?) >females are less adept `spatially' than males. No the effect was first noticed in humans, not voles, and is unquestionably present. The tests on humans are much more extensive and the papers showing the difference probably run into the hundreds. The problem with humans is that advocates of environmental influences claim that the differences are due to environment not nature. (In other words, little boys are treated differently than little girls and somehow this results in their doing better on tests of spatial ability). Since it is unethical to control the rearing environment for humans, animal experiments must be resorted to. The finding of the same differentials in animals that are found in humans makes the environmental argument much less tenable. Another interesting study that would implicate heredity is the work of Jerre Levy (U of Chicago female neuropsychologist) on Turner's Syndrome. Turner's patients have only one X chromosome. Their spatial ability is terrible (in fact their score on the performance part of the Wechsler is almost retarded). However, verbally, they test superior with average verbal IQ about 120. Further testing showed that their brains seem to be unlateralized (essentially two dominant (verbal) hemispheres). Again, I don't have the reference, but you should be able to find it with a computer search (paper appeared in the 70's). >>Why are females better verbally? >There is little good evidence that they are. There is superb evidence that they are. Maybe you meant evidence that they are *inherently* better verbally. The evidence that they test better verbally is incontrovertable and objective. Obviously no animal studies can be done on verbal ability. >An interesting speculation, yes, but do men in fact have a greater >lateralization? Well, 70 years ago women had more lateralized brains, >we were told. How is lateralization determined? Well, a lot of this >lateralization has been determined by a few studies that involved >autopsy of a dozen brains. You know what a dead brain is like? Sloppy, >that's what. I know what a dead brain is like, having autopsied them and been present for hundreds of brain autopsies. They aren't sloppy if they are fixed in formalin for three weeks before cutting. Quite precise measurements can be made. But why would measurement errors occur in a way to systematically effect female brains in a way differently than male brains? Only if there was some intrinsic difference, no? The 70 year-old corpus callosum studies you are talking about aren't the only way to determine lateralization. It can be done by measuring asymmetry in temporal lobe volume (less asymmetric in females) (these studies were done blind). In fact, you can even do imaging studies (CT, MRI) to show it, but that isn't the only way to show assymetry of function. I'm talking about psychologic and physiologic studies in live patients where lateralization can be determined without an autopsy. Such determination must be done prior to epilespy surgery, so many of these techniques were developed for that purpose. Brenda Milner is the psychologist most associated with the early studies here. BBS is a good source, but most people won't want to read that. Check out the chapter on Sex and lateralization in Sally Springer's book: "Left Brain Right Brain" (get the latest edition, more has been added recently) for a good discussion of the literature on gender differences in lateralization. Patricia Churchland's "Neurophilosophy", and Norman Geschwind's "Cerebral Lateralization" are also good sources to start with. >>It is certainly proven true that males are less capable of recovery from >>aphasia after a dominent hemisphere stroke than are females. >Nooo.. It is certainly proven true that men seek out therapy more often and >for longer than women following a dominant hemisphere stroke. Does that prove >that they actually suffer greater deficit? I honestly don't know where you are getting such information! This phenomena has been known clinically by neurologists for over 100 years (long before "speech therapy" existed!) and was studied by Jeanette McGlone extensively in 1978. There were over 85 patients in her study and the males did 3 times (!) worse than females. No known speech therapy technique can come within *leagues* of making such an astounding difference in aphasia. She did not select her cases from those who sought therapy anyhow, but where in the world did you get the idea that men seek therapy more often and for longer than women? This is entirely counter to all other studies that have ever been done that show that women seek medical care far more often and are more compliant with therapeutic programs than men. Any physician can tell you from experience the many cases of the husband who is finally dragged to the doctor at death's door by his concerned wife. I also refer you to the work of Hanna and Tony Damasio regarding aphasia recovery.