@Pixy
gender bias and bias that we all make unconsciously. (Not all black people are drug runners/gangsters, not all Scots are ginger, not all Welsh are sheep shaggers, etc, etc).
Pixy, what you wrote suggests an important but subtle point. Confirmation bias is not a "bias" in the way we often use the term. It is, instead, merely an unconscious process in our brains that gathers, interprets, and stores data to support what we believe.
This is extraordinarily powerful and, interestingly, it can be used to accomplish valuable social change. For example, in one study (and others of similar design have delivered similar results) women and men entering a very demanding Canadian engineering college were exposed to a very brief experience of watching videos of upper level students explain that the professors would challenge them in class because they wanted them to really learn the material, but that they would also be there to help them if the students would just ask. A control group received a different experience focused on managing stress. The group exposed to the belief --delivered by their slightly more experienced peers -- that challenging behaviors by professors were designed to help saw little difference in the performance of males, but females not only earned better grades, they also had better opinions of themselves as engineers and made more friends among the male members of the class (rather than making friends with those pursuing non-engineering studies).
That's huge! Think about the impact on the men who came out with women engineering friends! Basically, those women re-shaped their worlds, and, in fact our world, just because they were given a belief that let them interpret challenging behavior from professors as "this happens to everyone because they care" instead of "he's discriminating against me because I'm a woman." And then they went out into their careers with better views of themselves as engineers and more male engineer friends. What a difference those women are probably making in their professional lives! They're changing the world, and what started it was the seed of a productive belief implanted at the very beginning of their university experience on which their confirmation bias worked, day after day, gathering evidence to support that belief.
So: Confirmation bias is a process, not a belief. It supports the beliefs we hold; it does not determine those beliefs.
If anyone is interested in the study, here's a link to a copy.
ETA: I should add that my comments are NOT a claim that women in engineering, or other male-dominated fields, or in anything, for that matter, don't face anti-female beliefs and actions. I am suggesting that the way these women experienced their studies was altered by a productive belief (reinforced by the confirmation bias process in their brains) in ways that benefitted them and society in general, and probably would, over time, result in reduced sex-based discrimination.