Confirmation bias can do a lot of damage. Someone can hear a million things from doctors and experts that go against their deeply held beliefs, but if they hear one doctor out of a sea of naysayers articulate a take that they agree with, they might take it to the end of the world. After all, that’s the foundation of the anti-vax movement. One British doctor in the 90s said that taking the measles, mumps, and rubella vaccine all at once might cause autism (it doesn’t) in a now redacted paper 20 years ago, and people are still running with that despite its results never being replicated ever again.
Facebook groups are breeding grounds for confirmation bias. It’s so easy to make a post stating your opinion, ask if any of the other mamas feel the same way, and get flooded with support and encouragement, regardless of whether you’re right. If you want your bias that mommy Facebook groups are stupid to be confirmed, boy howdy, have I got the list of cringe parenting posts for you!