When people speak a native language the way people around them speak it, they assume that they do not have an accent. Accents are for outsiders. We ourselves speak the correct way.
The same applies for biases. Our mind constantly shifts its frame of reference on any issue to what we hold to be dear. If we thought we were biased, we would make corrections accordingly.
“Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?” – George Carlin
And yet, all of us have accents. A South Indian will talk about a “North Indian English accent” (and vice-versa). An American will tell you how all Indians have an “Indian English accent”. A Britisher could point out all the quirks of an “American English accent” and everybody in the room would agree about the existence of a British English accent, except perhaps the Brit.
The only way to not have an accent is to not speak a particular language. I do not, for instance, have a Japanese accent.
Biases, like accents, are inevitable if we know anything about a topic. Biases are like pieces of spinach stuck between our incisors. We easily notice them in other people, but fail to see them in our own selves. But that doesn’t mean they don’t exist.