Dr. Thomas Sowell wrote a book on it and a number of columns -- not a study exactly. But he tried to do a scientific analysis of the commonalities of late-talking children. His child did not talk until very late and has been diagnosed on the autistic spectrum.
I purchased the book for my daughter when we were first noticing Andy's problems, but the doctors were denying that there was a problem.
I think Sowell's book is called "The late talking child", or something like that. In any case, he wrote a column about his son and his frustrations of raising him as a single dad. The response to the column was so great that he formed a support group to share backgrounds and stories. He then put all of the resulting information into a matrix, or data base, and made some very interesting observations and wrote a book sharing some of the stories. His observations may, or may not, have any validity -- as he freely admits.
Sowell wrote that he did not have time to continue this research and do a proper study, but he offered his preliminary findings to any scientist who wanted to take this on as a project.
Among his findings was that something like 90% of autistics have an engineer, mathemetician, or musician, in their close family -- father, mother, grandfather, uncle, aunt. That one lept out at me and made me wonder why ALL of my grandchildren were not autistic, to say nothing of my own kids!
BTW, Sowell's son (who must be high functioning) eventually learned to talk and has graduated from college and was pursuing a career in computers at the time the book was written -- 10 years ago. As I remember, Sowell's son learned to play chess before he learned to talk.
You mention that "something has happened in the last 25 years". THree things, I think.
1)The definition of autism has widened.I do believe that to certain sensitive children, the vaccinations are an exacerbating problem. My compny health plan provided me with a handy chart yesterday on childhood vaccinations that are now required -- a baby is vaccinated for 15 different diseases by the time he is 15 months.
2) Parents no longer hide these children from the public.
3) The number of vacinations given to babies in recent years has multiplied exponentially.
I noted that the MMR is now recommended at ONE YEAR! That is the vaccination that is suspect in my grandson's autism and he received it in its mercury-laced form at 15 months. He might have been fine, had his parents put it off until he was 2 or 3. His younger brother had those shots separated and administered much later, and he is just fine.
Among his findings was that something like 90% of autistics have an engineer, mathemetician, or musician, in their close family -- father, mother, grandfather, uncle, aunt. That one lept out at me and made me wonder why ALL of my grandchildren were not autistic, to say nothing of my own kids!
My brother was a musician, a brilliant musician and mathemaetician. My brother had full scholarship to MIT before he left for the New England Conservatory of Music. And my sister-in-law's Father was an engineer of the highest caliber. She herself a very talented musician.