The Linda Problem

Linda is a single, 31 year old woman who majored in philosophy, and she is very outspoken in her views. During her time as a student, she was profoundly concerned with discrimination and issues of social justice. She also participated in anti-nuclear demonstrations.

Which of these is more likely?

1. Linda is a bank teller.

2. Linda is a bank teller and is active in the feminist movement.

It might surprise you (because you’re smart) that most people asked this question will typically choose the second option.

Amos Tversky and Daniel Kahneman named this phenomenon conjunction fallacy, but it’s just as commonly called “The Linda Problem.” What’s going on here?

First, let’s talk about the logic. When you have two choices, and one choice means X has to happen, and the other means that X has to happen and something else must also happen, the first choice is automatically more likely to happen. This is about as basic as probability gets, and we humans understand this at some level.

So, why do we make the mistake?

We start to get a mental picture of who Linda is during the description. We imagine that she is a particular type of person who would be single, 31, into philosophy, outspoken about social justice and nuclear disarmament. From there, we latch onto this knowledge about Linda.

In short, we create a stereotype.

We’re married to the idea that she is all of these things, and that stays front and center in our minds as we answer the question about which scenario is more likely.

Linda is a bank teller.

This seems like it’s possible, but it doesn’t really have anything to do with our Linda.

Linda is a bank teller and is active in the feminist movement.

Now we’re talking! If she was going to be a bank teller, it would be one who is also active in the feminist movement.

Our minds are capable of leapfrogging logic in order to make our internal story more consistent. The stereotype is the tool we use to make this dangerous cognitive leap.

Conjunction fallacies are everywhere in the 21st century world. If someone lies to you, there’s a good chance they’ll embellish the tale with more information than necessary. This fallacy can be a helpful tell—a way to determine someone is lying.

You might also come across this Linda Problem in the world of advertising and marketing. Ads use the power of association all the time to make us imagine that someone is living their best life, all thanks to whatever it is that they’re selling. By showing us incredibly specific visions of our future (with their product or service), they utilize the same logic leapfrog that the original Linda Problem does.

Being aware of this tendency can help you avoid walking into its most common traps. It seems obvious when you say it out loud, but in that moment, your mind wants to move quickly past any objections you might have and conclude that the association is the most important thing. We have to slow things down and consider logic.

Have you ever noticed this fallacy in the real world? What are some other examples you’ve seen?