Many of us have seen the game show, Let's Make a Deal. Those of us who have seen it probably remember the game in which the contestant must choose between door #1, door #2, and door #3. In this game, there is one door with a nice prize and two losing doors. The contestant must choose which door the prize is behind. After the contestant chooses one of the doors, the emcee (Monty Hall) opens one of the losing doors in order to show that there is still a chance of winning the prize and to raise the contestant's blood pressure. Then the contestant is given the option to stay with their original choice or to switch doors. After choosing, another door is opened that reveals whether or not the contestant actually won the prize. In the experiment that will be described in this paper, the above mentioned game is played using only a deck of cards. The subjects (n=17) are told that there is one winner (the ace of spades) and there are two losers (jokers). Then they are asked to point to the card that they believe is the winner. The game proceeds exactly as the above mentioned game. After seeing the results, the subjects were each given an explanation of why switching choices would be beneficial to them and were asked whether or not they would switch in the future. What is looked at is whether or not people stick to their original choice when given the option to switch, whether or not the subsequent explanation convinces them that switching choices gives them an advantage when playing this game, and possible reasons for their decisions. This paper will attempt to support the hypothesis that people tend to stick with their first guess.

Of the 17 subjects in this experiment, all 17 initially chose to stay with their first choice. Of these 17 people, only 3 correctly guessed where the ace of spades was located. None of the subjects originally believed that their chances of winning would be affected by staying or switching. After the explanation, however, 2 of the correct guessers and 12 of the incorrect guessers said that, if given another chance, they would switch in the future. When asked why they stayed with their initial selection in the first part of the experiment, 6 of the subjects said that they went with their instinct, 8 subjects said that it has to be behind one of the doors and they would hate to switch, and then lose, and 3 of the subjects responded with "I don't know". Of the 3 subjects that would not be swayed by logic, all 3 were in the "instinct" group. And of the original 17, there were 6 subjects who said "I knew I should have switched". Three were in the instinct group and 3 were in the "I don't know group".

As hypothesized, most (all) of the subjects stayed with their original choice rather than switching. There are several psychological principles that can explain why this happens. One of them is regret theory. Since there is more immediate regret for actions taken and more later regret for actions not taken, a person may choose not to switch because then they would have to deal immediately with knowing that their original choice was the winner. If they choose not to switch, then they can rationalize that the winner could only be one of the choices, and that they made the best choice that they could possibly make.

Another possible reason for the refusal to switch is the endowment effect. In this situation, the subject would have to quickly decide that whatever is behind that door (or under the card) is what they have won. They would have to believe that they have chosen correctly and have thus added to their personal wealth. If they believe that their choice is the right one, then there is a potential for loss aversion. The person may feel safe with their choice since there is a one in three chance of winning, and a perceived 50% chance of winning after being shown a losing door. They simply may not want to part with what they have come to believe is their possession.

People will not, unless educated in probability theory, tend to second guess themselves when making split second, potentially life changing, probability based choices. They will put the results in the hands of chance, they will rely on instinct, or they will not know why they make a decision. However, as the results of this experiment show, when people are educated on how they can increase the odds of a favorable outcome, they will tend to learn from this education.