*This is a guest post by Brian Potter of Coarse Grained. It explores a different aspect of some of the ideas in my post, The Return of the Barbarian, and Paula Hay’s guest post, Cognitive Archeology of the West. If you are interested in guest-posting, email me. *

Consider the following experiment (the Wason selection task):

You are shown a set of four cards placed on a table, each of which has a number on one side and a colored patch on the other side. The visible faces of the cards show 3, 8, red and brown. Which card(s) should you turn over in order to test the truth of the proposition that if a card shows an even number on one face, then its opposite face is red?

The correct answer is “8” and “brown”, but very few people get the correct answer – between 10-25% depending on the exact formulation of the problem. Even when its expressed in more familiar terms, such as “If a person goes to New York, then he takes the subway”, success rates remain extremely low.

However, consider the exact same problem, rephrased slightly:

You are shown a set of four cards placed on a table, each of which has a number on one side and a statement on the other side. The visible faces of the cards show 16, 25, ‘drinking beer’ and ‘drinking coke’. Which card(s) should you turn over in order to test the truth of the proposition that if “If you are drinking alcohol, then you must be over 21”?

Phrased like this, success rates shoot up to around 75%. But what makes this form different than a question about riding the subway?