Causal Models At Work

[Epistemic status: loosely based on a true story]

AIDS Specialist: You know, people think AIDS is a death sentence. But how long do you think the average person lives after getting HIV?
Me: I don’t know.
AIDS Specialist: Thirty years! Isn’t that amazing? You can get HIV, and probably you’ll live another three decades!
Me: Really?
AIDS Specialist: Yeah.
Me: So, the trick is, give yourself HIV when you’re eighty, then live to be a hundred ten.
AIDS Specialist: I like you.
Me: Really?
AIDS Specialist: No.

And a few weeks later:

Me: Do you have a family history of alcoholism?
Alcoholic Patient: No. Why?
Me: Well, I am trying to figure out whether to prescribe you this medication, and studies suggest it works best in patients with a genetic predisposition to alcohol abuse.
Alcoholic Patient: I don’t understand.
Me: The medicine only works if one of your parents drinks too much.
Alcoholic Patient: Well, I think I can get my dad to start.
Me: NO!