Posted by jlwile on March 11, 2010
The “Monty Hall Dilemma” is a classic probability problem that stumps most people. Named after the original host of “Let’s Make a Deal,” it begins with three curtains. Behind one curtain is a car, and behind the other two curtains are goats. The participant chooses one curtain, and then one of the two curtains not chosen is lifted, and it always reveals a goat. The participant is then asked whether he or she wants to stay with the original choice or choose the other unlifted curtain. What should the participant do? Does he or she increase the chances of winning the car by switching or should the participant hold on to the original choice? Does it even matter?
The answer is that the participant definitely increases his or her chances of winning by switching the choice. When all three curtains were down, the participant had a 1-in-3 chance of winning the car and a 2-in-3 chance of picking a goat. Thus, the participant is more likely to choose a goat. Once a goat is revealed, however, one wrong choice is removed. If the participant stays with the original curtain, the chance is still 1-in-3. Thus, the curtain that is still down but unpicked must have the remaining probability for the car, which is now 3-in-3 minus 1-in-3, or 2-in-3. So the remaining unpicked curtain is more likely to have the car behind it, and this means the participant should switch. I have explained this to many, many people, and most would not accept the explanation, which is correct. 1
Well, it turns out that one of the people who did not believe my explanation rather sheepishly sent me the reference to a great article demonstrating that pigeons are better at people in figuring out this dilemma.
The article reports on a study done by Walter T. Herbranson and Julia Schroeder.2 In the study, the researchers presented a pigeon with an apparatus that had three keys. The keys would light up to show that bird feed was available “behind” one of the three keys. The pigeon would peck one key, and then one of the two unpecked keys that did not have bird feed would turn off. Now there were only two lit-up keys, and the pigeon had to choose again to have a chance at the bird feed. The pigeon could peck the same key again or the other key that was still lit. This experiment was conducted on several pigeons for many days, and the birds quickly got the right strategy. After thirty days, almost all of them had begun switching the choice after the first key was turned off.
What’s really cool is that twelve undergraduate students were given a similar test, and even after 200 trials, they had failed to adopt the correct strategy. Thus, at least when it comes to probabilistic problems like the Monty Hall Dilemma, pigeons seem to be smarter than people.
What does this have to do with evolution? Well, there are two things to consider. First, the intelligence of chimpanzees is often used as evidence that people and chimps share a common ancestor. Just as similarities in biological structures are supposed to indicate common ancestry, similarities in behavior and intelligence are supposed to indicate the same thing. Of course, as Simon Conway Morris has shown in his book Life’s Solution, we know that’s not really true. There are many instances in which similar structures and similar behaviors cannot be the result of common ancestry. This study simply adds to Morris’s already spectacularly successful catalog of such instances.
The second thing to consider is what the researchers said about why pigeons might be better at this dilemma than people. According to the researchers, pigeons seem to be very empirical. They try things out to see what works, taking their lead from the “data” that they collect. Humans, on the other hand, develop “rules of thumb” that they use to interpret the world around them. Such rules of thumb are nice, but they can often fool people to go against the data.
As a scientist, I cannot imagine how anyone can honestly look at the data and seriously believe in evolution (as meant colloquially – fish becoming amphibians, etc.). The data simply do not support the idea. Of course, since I was trained as an experimentalist, perhaps I think empirically. Perhaps some evolutionists are so locked into their “rule of thumb” of common ancestry that the data aren’t as important to them. Thus, instead of letting the data lead their thinking, they force the data to conform to their “rule of thumb.”
All I can say is that in this case, I am glad that I think like a pigeon!
1. Donald R. Mack, The Unofficial IEEE Brainbuster Gamebook, p. 76, 1992.
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2. Walter T. Herbranson and Julia Schroeder, “Are birds smarter than mathematicians? Pigeons (Columba livia) perform optimally on a version of the Monty Hall Dilemma,” Journal of Comparative Psychology 124:1-13, 2010.
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