We still don’t know the root causes of autism, but researchers have pieced together many factors that correlate with the disorder. Now, some scientists are prepared to add intelligent fathers to the mix. A new study of more than 300,000 Swedish military families, presented at the 2017 International Meeting for Autism Research in San Francisco, suggests that a child’s chances of being born with autism increase by one third when the father’s IQ is 111 or above.
“Seeing this association with a high paternal technical IQ is interesting,” Renee Gardner, assistant professor at Karolinska Institutet in Stockholm lead investigator on the study, told Scientific American.
For the study, Gardner and her colleagues looked at the medical records of 309,803 children whose fathers were members of the Swedish military. After controlling for socioeconomic status, parental age, education level, and history of inpatient psychiatric treatment, they found that fathers with technical IQ scores of 111 or above had a 31 percent increased risk of having children with autism, compared to fathers with IQs that clustered around 100.
Not that having a smart dad is all bad. The same analysis suggests that men with IQs below 76 were 65 percent more likely to have a kid with ADHD and four times more likely to have children with some intellectual disability. The IQ sweet spot seems to be somewhere in the middle, but even that remains unclear since IQ tests are fundamentally flawed measures of intelligence. Gardner is aware of these issues, and was careful to tell Scientific American that the risk of autism due to high paternal IQ (or intellectual disability due to low paternal IQ) is “very slight.”
Still, the research echoes observations dating back to the 1940s, when Leo Kanner and Hans Asperger reported that children with autism tended to have highly intelligent dads in technical fields. And at least one 2012 study of children in the Netherlands found that autism is more prevalent in regions with high tech jobs. “It’s intriguing that this original observation actually holds up in our very modern-day data,” Gardner told Scientific American.
Intriguing, indeed. But like most intriguing autism research, the findings are certainly in need of further scrutiny.