Maybe the experimenters missed <yet another brilliant idea proven wrong in the last century>? Just kidding. What I ask instead is, Do people ever not suffer from conjunction bias?

I read about this experiment a couple years ago, about logic and intuition. (I’m writing from memory here, so it’s likely I screwed something up). People were given logical rules, and asked to find violations. Something like:

(Rule) If you are under 21, you can’t buy alcohol.

1. Bob is 24 and buys alcohol. (That’s not a violation)

2. Tom is 18 and buys alcohol. (Most people spotted this violation).

(Rule) If you go to France, you can’t drive a car.

1. Bob goes to France and takes a subway. (Not a violation).

2. Tom goes to France and drives. (Fewer people spotted this violation).

Of course it wasn’t easy like here, with a rule and a violation right next to each other. The rules were phrased more cleverly, too.

Anyway, people were better at logic when the situation was more intuitive. I wonder if any experiments have been done in which (untrained) people demonstrated a likewise absence of conjunction bias?

Maybe something like below would work, when you’re pointing out that (T) and (F) are occurring together.

Linda is 31 years old…

Please rank…

(F) Linda is active in the feminist movement.

(T) Linda is a bank teller.

(L) Both (T) and (F)

And if that doesn’t work… well, maybe better minds than mine had ALREADY done an experiment. Any suggestions for further reading, anyone? Summaries greatly appreciated.