You're playing a game with friends that involves flipping a coin: if it lands on heads you have to perform a dare, but if it lands on tails, you get to choose a friend to perform a dare.
After ten minutes you and your friends notice that the coin has landed on heads fourteen times in a row, and it's your turn. Do you pick heads or tails?
You pick tails, rationalising that because it has landed on heads so many times now, the next one has to be tails.
Congratulations! You've just fallen victim to the gambler's fallacy!
Casino de Monte Carlo
The most famous instance of the gambler's fallacy occurred at Casino de Monte Carlo in the summer of 1913.
After the ball at a roulette table landed on black twenty times in a row, gambler's flocked to the table to place their bets on red, reasoning that the unexpected streak was a sign that red was due.
Round after round the ball continued to land on black. It wasn't until the twenty-seventh round that it finally landed on red, but by that time millions was lost due to the gambler's fallacy.
The lottery
You're at a friend's house for dinner when your friend makes a wild claim:
"I'm going to win the lottery this weekend, what shall I buy first?", he says with confidence.
Confused, you ask: "What makes you think you're going to win the lottery? I'm quite sure it's not predetermined!"
"Well..", your friend says, "...you know I've been playing the lottery for years and I've never one more than a few dollars. That can only mean on thing: I'm due a big win!"
What can we do about it?
Having a good understanding of probability is a sure-fire way of reducing your vulnerability to the gambler's fallacy. Knowing which events are mutually exclusive and which are not will help make reasoning about future events easier.
As comforting as it is to believe that there is a balancing force in the universe, it's simply not true: what goes around doesn't always come around.
Banner photo by Steven Depolo used under the CC-BY-2.0 license. Changes were made to the original.
Casino de Monte Carlo photo by Janice Waltzer used under the CC-BY-2.0 license. Changes were made to the original.
Other posts in the series:
- The lies we tell ourselves - the sunk cost fallacy
- The lies we tell ourselves - the framing effect
- The lies we tell ourselves - cognitive dissonance
- The lies we tell ourselves - confirmation bias
If you liked this post, or any others I've written, don't forget to follow me.