What recent experience taught (or re-taught) you how difficult it is to transcend your biases? Haven't had an experience like that lately? Allow me to suggest you volunteer - as I recently did - to register voters. If you pay attention to your thoughts while doing this, I suspect it will be revelatory.
Following a brief orientation and review of the relevant forms, I joined a few other volunteers at a local street festival. The simple question to be asked of people passing by our table was - Are you registered to vote? Although not instructed to do so, I responded to every "yes" with an enthusiastic thumbs-up. If someone was unsure of their registration status, the orientation had prepared me to ask clarifying questions. More experienced people were also nearby to assist me if need be. For anyone who was sure they were not registered, I had the necessary forms in hand. And our table was located about five yards from a US mailbox if any unregistered voter wanted to fill out the form right there instead of filling it in at home and mailing it via the postage paid envelope. Pretty straightforward, right?
Not so much. Not long after starting, I realized that although I was asking a lot of people if they were registered to vote, I was not asking everyone. My first thought was a logical and probably partially accurate explanation - no one would be asking everyone - some folks had to pass me by. But then I detected an emerging pattern connected to the folks I was asking vs. some who I let pass by. I also noticed I was paying attention to what was imprinted on the hats, T-shirts, etc. of certain folks. As my time at the table ended, I was exhausted from all the thinking about my thinking.
Though what I'm revealing here isn't ennobling, I suspect my thought processes are not unique. But in my next turn registering voters, I'll be more on guard vis-a-vis my biases when asking others that simple question.