Heuristics and Bad Choices.
“Tom is a very petite and frail man, who lives in Iowa. He is extremely detailed oriented, and will spend a great deal of time organizing his paperwork and personal effects. In social settings, Tom is well known for being meticulously clean and well dressed. Tom speaks very eloquently and is knowledgeable about many different academic areas. Tom attended university in at a state university in the Midwest, and graduated at the top of his class within his major."
Is it more likely that Tom is a farmer or a librarian?
When asked this question, what information did you use to come up with your answer?
Most of us use what is called the availability heuristic when answering such a question. We consider the facts as they presented to us, and we build something in our mind that closely reflects how we interpreted the information provided. Our mind goes to the closest available prototype we can come up with. When given only this information, most of us would picture in our minds and academic looking individual who would fit into the preconception of a librarian.
Let’s rephrase our introduction of Tom…
“Tom is elderly man who appears to have had a long and productive life. Tom lives in a rural state. Tom keeps his few possessions in very good working order, and will spend much time ensuring his paperwork is in order through the year. When Tom goes to town, he is always cleaned up and never wears work clothes. People in town seek out Tom’s sage-like advice when they have problems at work; he proudly tells people that he is both book smart from attending college and street smart from years of work.”
The availability heuristic would tell most of us that this must be another Tom! This cannot be the same individual that was talked about before. This “down home”, quintessential man of the land is without a doubt a farmer, no?
What we failed to take into account is some information that would have help desk in this venture. So let's up the stakes a little bit.... Pretend you didn’t get the second introduction to Tom, only the first. I'm going to give you the exact same information as before, but require you to wager $1000 of your own dollars on the answer. Your answer or guess would not change because no additional information has been given.
To be fair, since you are being instructed to wager your own money, I'm going to allow you to ask one question about Tom. However as with all games there are rules. You cannot ask tom directly what he does for a living, or is he possesses traits or attributes that would be required for a person of the chosen profession. For example, you cannot ask Tom if he possesses master’s degree in library science, nor can you ask him if you'd ever driven a combine. You cannot ask him what clothing he wears to work as that would indicate his profession. You can, however, ask him where he lives, what is favorite television show is or what his hobbies are.
Given the ability to ask one question, most people would choose a question that would try to confirm their initial analysis. Therefore if they ask tom where he lives, any answer he gives will be seen as confirming their initial analysis. If Tom response that he lives in Iowa, you would automatically compare your prototype for an Iowa farmer verses the description of Tom; therefore your initial analysis that he is a librarian is confirmed.
According to Daniel Kahneman, psychologist and expert on decision making heuristics, there is a much better question you should ask Tom. Let's first assume most people believe to be the correct answer is, from their availability heuristic, that tom is without a doubt a librarian. But the simple piece of information it doesn't even need to be asked because we already intuitively know it, is the information that should change most peoples wager:
How many male farmers are there in the world in comparison to the number of male librarians?
We know without researching, without Googling, without scouring Wikipedia, that there are substantially more farmers in the world than librarians. In the United States, the ratio of farmers to librarians is over 20:1!
Does this change your answer when you're putting your money on the line? No matter how we describe Tom, you are a huge underdog if you put your money on the fact that tom is a library. Without confirming evidence that tom told you he is a librarian or you see him working at a library, smart money goes on the fact that Tom would be a farmer.
If we wanted to get tricky, the introduction to Tom could have even included that he possesses a master’s degree from an Ivy League school. While it is true this is of little benefit to a farmer it still doesn't change the fact that the total population of male farmers far outweighs the total number of male librarians. Though the prototype in your mind would be screaming at you that Tom is a librarian, overcoming the small little statistician in your brain that is telling you that it’s a bad bet to claim Tom is anything but a farmer.
How can we apply such information to everyday life? Sometimes this game doesn't have the happiest of endings.... You go to a wedding this weekend to witness two lovly people get married, both of whom recently divorced from previous partners. Yet they found each other and make each other blissfully happy. The availability heuristic told you that they are happy now, they both have been through a bad situation and therefore know how to deal accordingly, and you can never see this blissful moment changing. Yet the tiny little statistician in your head is screaming that there is well over a 50/50 chance this blissful moment will not last.
Or you're flipping a penny with a friend, and the last 5 flips have come up heads. You know the penny is on the up and up and not a fake, weighted coin, so you offer your friend 2 to 1 odds that the next time it will come up tails, because tails is it "due"... forgetting to take into account that each flip is an independent trial but has no memory. The availability heuristic in your mind is telling you that it must come up tail soon... and the statistical part of your brain gently cries to self to sleep in the knowledge that mathematicians don’t make bad bets.
Why is all of this important? Once we realize that we are sometimes awful at making inferences from information that is provided us, we can start to see that we need is much information as possible to make big decisions in our lives. We can’t assume we know what is going on in a situation from the limited knowledge we are given. We must strive to look deeper. In psychology this often times means putting aside our preconceived notions and gathering as much information as possible. When we perform initial assessments of new clients, even the most seasoned and professional clinician can fall prey to the availability heuristic and confirmation bias by asking questions that will lead to statement of confirmation to a preconceived notion. The same can occur with functional in applied behavior analysis. so often with problematic behaviors individuals, caregivers, parents and observers will believe that they know the function of the troubling behavior long before any analysis is complete, and will therefore use data analysis to confirm what they already believe.
It is not only a case where asking the right question is imperative, but also asking the simplest questions. Making international assumption will often times you information well past the point of no return. in poker, you can flopped a straight very easily but if there are 2 suited cards on the flop and someone continually bets into you will assume that they must have a flush draw since you already have a straight. However you are falling prey to forgetting that everyone (and everything) is susceptible to imperfect information. You know what you possess did you believe you know what other people process but you truly don't know. Understanding and accepting what you don't know is often the most important piece of information you can obtain.
So the next time you think you have the right answer because you have all the information that someone has provided you, consider that you might not have taken in all the needed information. When you consider that sometimes you are your worst enemy in gather all the information, we need not even consider that the person telling you the “facts” might be trying to get one over on you!
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Unless otherwise noted, all blog posts are authored by Bradley Mitchell, provost of MBPSI.