[Spoom]

I've found that the ease with which someone answers "I don't know" has a positive correlation with their wisdom in general. (Of course, if they answer "I don't know" to everything, they probably just don't care, and that's a separate problem.)

[yeukhon]

I don't necessarily disagree with you. I think it is true that having too many I don't know means the person is probably not familiar with the area he's facing. The I don't care part is probably a bit rare. You probably have to look at body language (i.e. facial expression, for example).

[TheChineseGirl]

I second this notion.