According to the University of Chicago:
"Bias is a pre-formed negative opinion or attitude toward a group of persons who possess common characteristics, such as skin color, or cultural experiences, such as religion or national origin."
So, should we ever be biased? And if the answer is yes then should we hide our biases for signaling reasons?
Or should we take into account that many people have irrational biases against those who possess different skin colors, religions or national origins. So perhaps a high percentage of any negative biases readers of this blog have are irrational and so maybe the best course for us rationalists in training is to work against having any negative biases.