People usually don't think of themselves as biased
I have been known to go to absurd lengths to counteract the possibility of becoming biased in a given situation. Am I perfect? Of course not. But practicing excellence with compartmentalization, and with counterfactualization, as well as with maintaining comfort in the face of constant doubt, are all good tools for allowing yourself to believe you are correct while expecting yourself to be biased. (This is intentionally inducing cognitive dissonance and then adapting to the presence of said dissonance.)
and are bad at evaluating how biased they are even if they acknowledge some bias.
Very much so. And I would not even begin to pretend that I am "perfect" in this area. But experience and the observations of others have shown me that I am the least likely person I know -- or have encountered -- to allow political, emotional, or biological (as in sexual, dietary, etc..) investment to interfere with my ability to take the outside view. Why this is so, I am not remotely certain.
I've also built up, over time, a laundry list of habitual behaviors designed to mitigate biases regardless of whether I am aware of them -- such as my habit of attempting to parse arguments down as far as possible, of demanding definitions for 'fuzzy' topics, of being able to persuasively reformulate the arguments of others in language consistent with their own positions (to demonstrate comprehension of their position as they understand it.)
A article in the Atlantic, linked to by someone on the unofficial LW IRC channel caught my eye. Nothing all that new for LessWrong readers, but still it is good to see any mention of such biases in mainstream media.
I break here to comment that I don't see why we would expect this to be so given the reality of academia.