Irrational Jokes

The Relevance of Context

Two guys are walking down the street when a mugger approaches them and demands their money. They both grudgingly pull out their wallets and begin taking out their cash. Just then one guy turns to the other and hands him a bill. 

"Here's that $20 I owe you." 

This is an example of an incongruity between the guy's rational behavior - paying back the loan - and the context in which he pays it back. Since he's being robbed, he might as well pay back the loan at the same time. Paying back the loan is perfectly rational, paying it back under these circumstances is not. That's what makes it funny. 

Differentiating the Rational from the Irrational

Two friends decide to take an expensive fishing trip to Montana but after a week of fishing they only manage to catch one fish. On the way home, one friend says to the other, "The way I figure it, that fish cost us $5,000."  "Yeah," his friend replies, "Good thing we didn't catch more." 

Jokes can help us recognize when we don't have a clear grasp on what is rational. They're gentle reminders that we aren't always the best judges of what's rational and what's not. In real life, irrationality is usually more subtle, but there are still practical consequences to these errors in rational judgment. 

Nearly everyone holds contradictory beliefs. Often times, sophisticated reasoning is required to enable both beliefs to be held consistently. Contradictions cause tension, which is basically an intellectual balancing act between one belief and another. Abandoning one belief to maintain our balance requires intellectual effort and dexterity, otherwise we fail to reconcile the tension and the contradictory belief remains.