Correlation does not equal causation!
The causal fallacy is a tactic that can trip up the best of us! Why? Our brains like to take shortcuts wherever possible (1). So when we see…
A followed by B .
Our brains want to jump to: A caused B.
While causation and correlation can exist at the same time, the two events are often unrelated.
Here is a current example of a causal fallacy.
Misinformer: “Autism is caused by acetaminophen (Tylenol) use and low folic acid during pregnancy. A report says so!”
Reality: One recent meta-analysis found a correlation between these factors and autism. But even the authors stress this does not prove causation (2). Other large-scale studies and reports found no clear link (3,4,5). Cherry-picking one study that shows a correlation and treating it as proof of causation misrepresents the science and ignores the bigger picture.
That doesn’t mean research should stop, only that right now, the evidence does not support a causal connection, even if some studies hint at correlation (6). In other words: Just because a rooster crows before the sun rises doesn’t mean the crowing makes the sun come up.
This claim is also dangerous: acetaminophen is one of the few safe pain relief options for pregnant people. Suggesting they avoid it could leave them without safe treatment when they need it (6,7). Like any medication, acetaminophen isn’t perfect, and has well-known side effects if overused. But there is nowhere near enough evidence to suggest it causes autism. If you are pregnant and in pain, talk with your doctor or pharmacist to make sure you’re using it safely for both you and your baby.
We’re here to help answer your questions! Don’t hesitate to send us a comment or DM. And share this post as a good critical thinking reminder!
- Reason’s Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing | Journal of Neuroscience | March 2017
- Evaluation of the evidence on acetaminophen use and neurodevelopmental disorders using the Navigation Guide methodology | Environmental Health | August 2025
- Acetaminophen Use During Pregnancy and Children’s Risk of Autism, ADHD, and Intellectual Disability | JAMA | April 2024
- FDA Drug Safety Communication: FDA has reviewed possible risks of pain medicine use during pregnancy | U.S. Food & Drug Administration (FDA) | January 2016
- Prenatal acetaminophen use and outcomes in children | American Journal of Obstetrics & Gynecology | March 2017
- Upcoming HHS report will link autism to common pain reliever, folate deficiency in pregnancy, Wall Street Journal reports | CNN Health | September 5, 2025
- Tylenol has entered the chat: RFK Jr. wants to link it to autism, even though the best evidence says otherwise. | Inside Medicine | September 6, 2025
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