Ignorance more frequently begets confidence than does knowledge.

— Charles Darwin, 1871

Per my request for a “productive” summer my new advisor at A&M sent me a data set to figure out. After some preliminary analyses, our data looks like what is already found in the literature. Let me explain, Dr. Geraci asked her post-secondary students to predict what they would earn on each of 5 exams immediately before taking the exam. As an incentive to be as accurate as possible, she gave them a few points extra credit if they were close. What I found was that people are not good guessers, or they have poor metacognition. However, this is not a new idea. Furthermore, there seems to be interaction, where the bottom quartile performers grossly overestimate their performance, and top quartile performers underestimate how well they think they’ll do. The question is, why are people so poor at guessing? Is it because (a) the information necessary to make accurate guesses is not available or (b) the information necessary to make accurate guesses IS available and participants choose to ignore it?

Not surprisingly, there is evidence that supports both theories. Recenlty Gramzow and colleagues 2008 found overestimation feels good per vagus nerve activity (i.e. Respiratory sinus arrhythmia) which supports theory (b). Our data supports (a) simply because their is an incentive to be correct and people are still not guessing well. However, the gravity of a “few points extra credit” is suspect. Sounds ripe for more work. 🙂

-Posted by Tyler

  1. Huh, no, I don’t read Tdaxp. I will say that I think that “Chemistry” post is poorly developed after reading it, though. Is it tongue-in-cheek or serious? I can’t tell. And why make it so prominent that he’s a “doctoral candidate.” Big whoop; just another grad student.

    I post under “schencka.”

    Self-evaluation may occur in a “moralistic” part of the brain, so the skilled don’t want to tout their own stuff, because that, in effect, is touting their own stuff.

    Or the cognition may take place in different areas of the brain for the successful/confident and the unsuccessful/insecure.

    As an instructor, I see that people do not perceive evaluation in the same way they do other peoples’ evaluations. Easier to judge others than oneself.

    That’s a real perpetual question, isn’t it — why can’t people accurately self-assess?

  2. Hey Adam, thanks for your comments. I was hoping you’d have some feedback given your occupation.

    It could be that high performers “don’t want to tout their own stuff” as you said or they fall prey to the false consensus effect (i.e. they think they’ll do well, therefore the test is easy, therefore everyone else will do well.

    You said it may be easier to judge others than oneself. This is definitely true for high performers. In contrast, low performers, if given social comparison information (i.e. others’ scores) they will still overestimate.

  3. Interesting stuff. I’m not sure insecurity is necessarily tied to the unssuccessful. Certainly it could be argued that more successful people are more confident but I don’t believe that assessment encapsulates the whole. I would consider the idea of expectation placed on one’s self. If you are prone to being more successful, then you likely place higher expectations on yourself. This is likely where the successful can be insecure. If you always have your expectations set at 100%, either you will guess 100%, which is statistically improbable because we are human and therefore fallible, or you will guess realistically and always undercut your expectations. It is a little more difficult with the lower performers. Perhaps they base their estimation less on rational and more their comfort level regarding the test. If you don’t have particularly high expectations of your performance you won’t be as stressed when you have to take it. You might overestimate your ability because you feel rather than think. Maybe it’s not a question of expectation but aspiration with the lower performers. They shun realistic thought in favor of optimistic thought. Then this brings up the idea that they were to receive bonus points for accuracy. This isn’t a huge incentive and I would guess people guessed lazily. I should probably work. I just wanted to throw my hat in the ring.

  4. Thanks Mike, You are partially right about the probability issue. High performers underestimating and low performers overestimating is a mathematical verity. Low scorers simply have more room to overestimate whereas high scores do not, they have more room to underestimate.

    Where the math verity explanation breaks down is in the difference between guess & actual score. The difference for low performers is 4x that of high performers. So what gives?

    Perhaps laziness is the issue. If trained participants can calibrate their guesses to match their scores but only in the domain of training (e.g. logical reasoning).

    Whats more, it feels good to overestimate to boot. Why not be lazy and feel good?

  1. October 12th, 2008

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