Limited data. Unlimited assumptions. – Satheesh Krishnamurthy

Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a, she was deeply concerned with issues of discrimination and social justice and also participated in anti-nuclear demonstrations.

Now that you have read about Linda, which one of the following two scenarios is more likely to be true:

Scenario One: Linda is a bank teller.

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

I bet you picked Scenario 2. If you did, pat your back. You are in the top 80% worldwide who picked the same.

Now, slap your head. You may be grossly wrong!

The chance of Linda being a teller, among millions of things she could be, is in itself highly unlikely. The second scenario is highly, extremely, incredibly even more so.

Let’s say the probability of Linda being a bank teller is as low as 0.05. Even if we presume the probability of her being a feminist is as high as 0.95, the probability of her being both a bank teller and a feminist is: 0.05 x 0.95 = 0.0475. This is lower than her simply being a bank teller. Yet, you picked a highly improbable scenario 2 over a fairly reasonable scenario 1.

Psychologists Amos Tversky and Daniel Kahneman who posed this question and posited this theory named it the Conjunction Fallacy. The probability of two events occurring in conjunction is always less than or equal to the probability of either one occurring alone.

Logically speaking, we should not pick option 2. Yet we do coz we correlate it with what Linda did in college. Put simply, we join the dots that don’t necessarily exist!

We make irrational assumptions based on limited data and jump to conclusions without understanding the information laid before us. Want to try another one?

Of the following two scenarios, which one is more likely to happen:

Scenario 1: You will have a flat tire tomorrow morning.

Scenario 2: You will have a flat tire tomorrow and a cute girl in a Scooty will stop to help you.

I know what you picked. Sorry, that’s not going to happen!