You Know What Really Causes Autism?: A Look at the Deluge of Recent Headlines



There’s been a recent flood of studies on the causes of autism, each one trumpeted in headlines that promise, “Now we can do something about this!” Is autism caused by prenatal stress? Too much testosterone in utero? Moms who take antidepressants? Who get infections during pregnancy? Who are overweight?  Dad’s job? Moms who are olderGrandfathers who are older? Moms who were sexually abused when they were kids?


And no.

The dazzling array of studies presenting links between life conditions—some of which we can do nothing about—is a reminder of one of science’s oldest and most potent truisms: Correlation doesn’t imply causation. What’s that mean? Well, there’s another name for this: the cum hoc ergo propter hoc logical fallacy. If A occurs in correlation with B—if, for example, moms who take antidepressants while pregnant are more likely to give birth to autistic children—then A causes B. Except it doesn’t, necessarily.

That’s why, earlier this year, a writer for the website IO9 produced a tongue-in-cheek chart showing the real cause of the increase in autism diagnoses in the past few decades was organic food.

Last century, the so-called “refrigerator mother” theory that autistic kids’ moms were distant and uncaring was widely accepted, by the public and the medical community. It’s little wonder diagnosis has increased as direct blame for the moms has waned—who would have admitted a child was having problems when it meant being pegged a refrigerator mom?

But so many different “causes” of autism are nearly as frustrating.

If my kid was on the autism spectrum, my heart would sail into my throat every time I saw a new headline purporting to tell me what went wrong—what I could have done differently, what I might still do, who or what to blame. But if there’s anything all these studies show, it’s that a host of things can go awry in the process of procreation and gestation. How they’re all interrelated is for the scientists to tease out, and it will take decades, at least. Whatever they discover, one thing’s for sure: Conceiving a baby is a crapshoot. It always has been.

