There are countless ways we hear this sentence.

“I never wore a seatbelt and it never hurt me.”

“I drank as a teenager and my brain wasn’t damaged.”

“My grandma smoked from the time she was 12 and died in her 90s — from old age!”

The “I turned out just fine” argument is popular. It means that based on our personal experience we know what works and what doesn’t.

But the argument has fatal flaws.

It’s what’s known as an anecdotal fallacy. This fallacy, in simple terms, states that “I’m not negatively affected (as far as I can tell), so it must be O.K. for everyone.” As an example: “I wasn’t vaccinated, and I turned out fine. Therefore, vaccination is unnecessary.” We are relying on a sample size of one. Ourselves, or someone we know. And we are applying that result to everyone.

It relies on a decision-making shortcut known as the availability heuristic. Related to the anecdotal fallacy, it’s where we draw on information that is immediately available to us when we make a judgment call. In this case, autobiographical information is easily accessible — it’s already in your head. We were smacked as kids and turned out fine, so smacking doesn’t hurt anyone. But studies show that the availability heuristic is a cognitive bias that can cloud us from making accurate decisions utilizing all the information available. It blinds us to our own prejudices.

It dismisses well-substantiated, scientific evidence. To say “I turned out fine” is an arrogant dismissal of an alternative evidence-based view. It requires no perspective and no engagement with an alternative perspective. The statement closes off discourse and promotes a single perspective that is oblivious to alternatives that may be more enlightened. Anecdotal evidence often undermines scientific results, to our detriment.

It leads to entrenched attitudes. When views inconsistent with our own are shared we make an assumption that whoever holds those views is not fine, refusing to engage, explore or grow. Perhaps an inability to engage with views that run counter to our own suggests that we did not turn out quite so “fine.”

Where is the threshold for what constitutes having turned out fine? If it means we avoided prison, we may be setting the bar too low. Gainfully employed and have a family of our own? Still a pretty basic standard. It is as reasonable to say “I turned out fine because of this” as it is to say “I turned out fine in spite of this.”