The Origin Story: What Actually Causes Autism?

When a child is diagnosed with Autism, the first question parents often ask—sometimes in a whisper—is: “Did I cause this?”

They replay the pregnancy. Did I drink too much coffee? Was it the stress at work? Was it that glass of wine before I knew I was pregnant?

The answer is no. You didn’t cause it.

Autism is not a result of “bad” choices. It is a complex biological difference.

Here is what science actually knows about the origins of the Autistic brain, and the myths we can finally put in the trash.

1. The Genetic Lottery (The Biggest Factor)

If you want to look for the “cause,” look at the family tree.

Autism is highly hereditary. Research suggests that genetics account for 50% to 80% of the likelihood of being Autistic.

  • It is Polygenic: There is no single “Autism Gene.” Instead, it is likely a combination of hundreds of tiny genetic variations.
  • The “Broader Autism Phenotype”: Often, parents realize after their child is diagnosed that they (or a grandparent) have “Autistic traits”—social awkwardness, a need for routine, or sensory sensitivities—even if they were never diagnosed. The apple rarely falls far from the tree.

2. The Environmental Puzzle

Genetics loads the gun, but the environment might pull the trigger.

However, “environment” doesn’t mean “how you raised them.” It refers to biological factors in the womb.

Risk factors identified by science include:

  • Parental Age: Children born to older parents (both mothers and fathers) have a slightly higher chance of being Autistic.
  • Prematurity: Babies born very early or with very low birth weight.
  • Pregnancy Complications: Issues that affect oxygen supply to the baby’s brain.

Note: These are risk factors, not guarantees. Most older parents have non-Autistic children, and many Autistic children had “perfect” pregnancies.

3. What DEFINITELY Does Not Cause It

Let’s clear the room of the two biggest lies that have hurt families for decades.

Myth A: Vaccines

  • The Truth: This myth started from a single, fraudulent study in 1998 involving only 12 children. The study was retracted, the doctor lost his license, and millions of children have since been studied. Vaccines do not cause Autism.

Myth B: “Refrigerator Mothers”

  • The Truth: In the 1950s, doctors blamed “cold” or unemotional mothers for their children’s Autism. This was cruel nonsense. We now know that parenting style has zero effect on whether a child is Autistic. You cannot “love” a child out of Autism, and you didn’t “ignore” them into it.

4. The “Different Wiring” Perspective

Instead of looking for a “cause” like it’s a broken leg, think of it like being left-handed.

  • What causes left-handedness? Genetics, mostly.
  • Is it a problem? Only if you force them to use right-handed scissors.

Autism is a natural variation of the human genome. It has likely existed as long as humans have. The “cause” is simply the infinite diversity of human biology.