Do you avoid them? Keep useful feedback away from them? Fail to encourage? Gossip about them?
Maybe you need to have a conversation with yourself, Asmus says.
--What biases or judgments are coming into play?
--How do I fret and reinforce these?
--Are my personal beliefs affecting this person's performance?
--What potential can I see in this person?
Consider actions you can take. If your behavior is affecting them--do you want to change your behavior?
Be patient. If you make changes in your approach (invite the person to lunch, to more meetings, include him or her on email blasts), is it affecting their work? Do you feel better?
Do it for yourself! You know what--this person may not care for you either! But this can change and an ally may emerge.