Everyone has bias

One of the first things one learns as a social psychologist is that everyone is capable of bias. We simply are not, and cannot be, all knowing and completely objective. Our understandings and views of the world are partial, and reflect the circumstances of our particular lives. This is where a discipline like science comes in. It doesn't purge us of bias. But it extends what we can see and understand, while constraining bias. 

Claude Steele, Whistling Vivaldi: And Other Clues to How Stereotypes Affect Us (New York: W. W. Norton & Co., 2010), p. 13