We all have biases that we should try to be aware of. Our implicit prejudices may be at odds with our explicit attitudes. One problem when discussing issues such as racism and sexism especially is that surprisingly many people seem to think that such things have been largely dealt with in the 20th Century and are now of minimal importance.
https://implicit.harvard.edu has several tests designed to measure our implicit biases. As with any scientific test, there could be issues with methodology etc and, in addition to discussion of implicit biases (e.g. the psychology of them, how they affect our skepticism), that also seems an appropriate topic for discussion here.