Hah. In discussing the methodology of the "camel has two humps" study with a friend who's an okay programmer, the idea came up that what they might have been measuring was overconfidence. People who are ignorant but overconfident would exhibit a consistent (but possibly wrong) model, whereas people who are ignorant and know it might hedge their bets by not answering consistently. Some courses and instructors (but not all) certainly do favor the overconfident student.