Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Medical Above average effect in psychology

  1. Oct 29, 2012 #1

    My book has a survey in it that is supposed to show you if you have these biases or not, but it seems so silly to me. I can see how it applies to intelligence, assuming that we are right all the time is a pretty adaptive bias in a lot of cases, but with other things it really does seem silly.

    For example there's one question

    How likely do you think you are to fail an exam?

    - More likely than the average person
    - the same as the average person
    - less likely than the average person

    And if you say more likely than average on all of your questions the idea is you have the bias.

    But I know myself, and I know my situation, I am studying psychology in university through a language I've only been studying 2 years. I am more likely to fail than the average person. This means I have a negative bias and I am depressed?

    You probably think that's an exception, but I can make arguments like this about every single question on the test.

    Now I know the idea is one of anchor and adjustment, you think "oh it's difficult for me, so I must be below average" and then you think "well it's difficult for everyone..." but you don't adjust enough for everyone.. but I think we are accurate in this.

    It seems like the premise of the whole thing is that most people are genuinely average.
    That's absolutely not true, most people are either above or below average. Wouldn't this make more sense if you took the mode into account rather than the mean?

    Next example

    Try to learn a new thing (cooking, learning a language, etc)

    I would say most people on this forum would be above average in this, since it's a learning forum. I'm always learning something new, and most people I know are, but I've met all the people I know either through school or through teaching or through interest groups that met because we were all learning the same thing. I feel like we are all above the average in this respect? Am I being really being irrational?

    Also they normally give these tests to undergraduates at university, who obviously are learning new things all the time! Of course they are going to write they're above average!

    The questionnaire is cited as by Chang, Asawa and Sanna, 2001

    I really don't think I am so amazing and special that I have seen a hidden flaw in an accepted theory, I assume I am wrong about this and the nice PHD people are correct and I'm missing some key feature, can someone enlighten me?
  2. jcsd
  3. Oct 29, 2012 #2


    User Avatar
    2017 Award

    Staff: Mentor

    You cannot conclude anything about biases based on a single answer. But if there are 100 answers and you mark "I am [better] than the average*" in 90 of them, it is likely that there is some bias present. It could be that you would really be better than average* in 90 of 100 cases, but it is highly improbable. If you answer "above average" in 40 questions, "below average" in 30 and "about average" in 30 (or similar numbers), that is more realistic.

    *I think it should be the median here, where exactly 50% are better by definition.

    But not everywhere at the same time.

    This requires to have questions about many different areas, of course. If you compare yourself to all others in 100 questions about your work, 100 times "above average" is not surprising.

    By the way: If you know that the test evaluates your bias, your answers will be biased, too, of course, which would make a nice meta-study ;).
    Last edited: Oct 29, 2012
  4. Oct 29, 2012 #3
    That makes sense, the book only gave a sample of about 10 questions so I guess I failed to see the big picture. Thank you!

    I wasn´t thinking of the median, but that would work too. I was thinking of mode, because say for example with juggling, many many many people can juggle only 2 balls, this is the mode but nobody can juggle less than 1 ball and a few people can juggle 6 and a few more 5 and a few more 4 and a few more 3.. so that even though the majority of people that you ask will say 2, you might end up with an average of 3.

    So if I say I think I´m a below average juggler because I can juggle 2 balls, I´m actually right, but the fact is I´m a perfectly normal juggler, because it´s normal to be below average in this case.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook