This is a real phenomenon, and not just your imagination. At least two different processes seem to contribute to consistently doing this:
- People, including students, unconsciously equate effort with accuracy. So if it takes 3 minutes to justify one answer and only 30 seconds to justify another, the 3 minute answer is often picked. Of course this usually means that it took more assumptions and tortuous reasoning to justify the 3 minute answer, which makes it less likely to be true. (Perhaps part of the reason for picking the more tortuous answer is fear one won't be able to recreate the logic again!)
- Students also frequently give more validity to impressions of "what your body wants to do" or "what the cell wants to do" than to actual known relationships or equations that describe reality. Often, a student will say something like, "Well, I knew that stroke volume times heart rate equals cardiac output, and answer 'b' fit that equation, but I though that stroke volume should be really important in determining cardiac oxygen consumption because the heart wants to move all that blood, so I chose answer 'c'." Notice the difference between "knew" and "should". How can I keep from doing this? Few, if any, of us can prevent this entirely, but you can decrease the frequency by actually writing a "truth score" next to the letter of the answer. Have faith in your score - if you've never heard of it, don't assume it's right (because you're sure you miss things) and don't assume it's wrong.
Use a 5-point scoring system (e.g. "++, +, +/-, -, --" or TT, T, ?, F, FF) to assign a "truth" value to each answer as you first read it — before you agonize over any of them. For example:
- TT is definitely true (you can write an equation or fact that demonstrates it).
- T is probably true (you can't think of a definite proof, but you have a hunch).
- ? is one you are really not sure of (don't assume it's true or false if you just don't know)
- F is probably false.
- FF is definitely false.
Think about each answer you aren't sure of, but don't change the original "truth" value unless you have a revelation of an equation or relationship you can actually write out.
If the one you are agonizing over gets a +/- or ?, but the original has a + or T, go with the original.