I agree with several posters who said that its likely more children whose parents are in the advanced ages are identified as gifted because they tend to be more educated, with better paying jobs, leading to be able to afford testing and search out more than those with less education.
I grew up poor, and nobody ever identified me as gifted, but that doesn't change who I was.
My DD was identified immediately by the school as someone who required screening for gifted services, with no intervention by DW or myself. So money didn't matter there, either.
I agree with Dude. The testing isn't what makes you gifted (and the OP didn't refer to testing), and public schools commonly test for IQ these days anyway. My kids have never been tested, but it's obvious (grade skips, etc.) that they're gifted.
What I was saying was that smarter, educated people TEND to have kids later, and that their kids tend to be smarter. This is not an absolute rule, obviously, but the trend has been increasing over the last 20-25 years or so as professional options for women have increased and as women's health has improved. When I was a kid, the doctors used to talk about having a baby past 30 as being "advanced maternal age" or AMA. Now AMA is defined as over 35 (well, around here at least).
A bit of Googling shows that the average age of first time mothers is increasing (
here�s an example with references to published studies). Plus, as women get older, the chances for chromosomal abnormalities in the child increase. These include Down syndrome and trisomy 18.
IMO (with some research studies to back it up), mom and/or dad's genes have a large influence on Junior's IQ.
Plus, it's relatively easy to take IQ points away from a person, but very hard to add them in and keep them there. And the potential increases are nowhere near as dramatic as the potential losses. This has been shown by many research studies, some of which debunked studies showing vast gains in IQ (AT MOST, these gains were short-lived). Long-lasting (smallish) increases in IQ are associated with adoption at or near birth into favorable circumstances out of unfavorable ones. As far as I know (please correct me if I'm wrong), this is the only way to achieve long-lasting upward changes in IQ.
Perhaps this will change as our understanding of neuroscience becomes more sophisticated.
