Originally Posted by Datura
How is that offensive? The premise is that people who were not genetically meant to be left handed may become left handed if something occurs during gestation.
Well, where I started getting my hackles up was when they said: "The team found that men whose mothers had scans were significantly more likely to be left-handed than normal, pointing to a higher rate of brain damage while in the womb." I was further disgruntled to read that "It is when the incidence of left-handedness begins to rise above these normal rates that scientists become concerned that brain damage of some kind could be a factor." (Gotta keep the left-handed numbers manageable... them southpaws will take over the WORLD if we're not careful! ;-)
Now... let's try a different physical characteristic: "The team found that men whose mothers had scans were significantly more likely to be green-eyed than normal, pointing to a higher rate of facial damage while in the womb." Are green eyes "damaged?" They're unusual, but really, isn't it a bit of a leap to say that this indicates damage
If the ONLY thing they were able to detect that was different was the rate of left-handedness, that may indicate (and I pointed out why it may not, as well) that ultrasound scanning CHANGES the way the brain works... but it is not the same as brain DAMAGE. Brain damage, even subtle damage, can be detected in all kinds of ways: IQ tests, perception tests, cognitive tasks, yadda yadda yadda. And there is NO correlation between this kind of identifiable brain damage
and left-handedness. I'm sure it would have been far too expensive to do that sort of testing on 177,000 men... but it would have made more sense than concluding that excessive lefties = brain damage.
I'm inclined to think that it was a flawed study, with a spurious correlation due to other factors (i.e. incidence of twinning in the family). But even if their data are solid, and ultrasound does cause a higher incidence of left-handedness, IMO that isn't a "risk." It's a side effect, perhaps. Actually, I'd tend to think of it as a benefit. ;-) But their whole attitude that there's something WRONG if more people are left-handed sits very wrongly with this third-generation leftie.