Monkey See Monkey Do: Bias For One Sex Is Learned

Bias for one sex or the other, and against one sex or the other, is generally learned by watching the way people treat one another during childhood, especially in our immediate families, but also in the larger community. Then when a person grows up, they generally judge the sex they are biased FOR through rose-colored glasses, assuming and projecting positive capability, motives, and character onto them. They tend to judge the sex they learned to be biased against through a cloud of negativity and self-righteousness, as if the members of that sex automatically deserve to be under a microscope and on trial.

Humans do the same thing with race and ancestry. Bigotry is bigotry, whether it's bias for or against another person's sex or race, or even age group.

Humans will do this regarding ancestry traits within their own race as well.

Those who we are biased FOR (either as a member of a group or as an individual) we "make way for", give more resources, respect, time, and positive attention to, willingly and respectfully assist them, recognize and honor their achievements, accomplishments, and character, and tend to believe in their capability, intelligence, and wisdom without making them "prove it". We also tend to believe them without double-checking their facts or doubting their motives. 

Those who we are biased AGAINST we tend to treat in the opposite way, whether we're biased against them as members of a certain group, or as an individual.
We'll nonchalantly or directly block them, dismiss them, argue with them, try to prove them wrong, and ignore them. We'll ignore, dismiss, and criticize their achievements and goals, and apply negative motives to them. We'll say negative things about them instead of positive things in conversation. We'll treat them as if they are incapable, inexperienced, weak, stupid, silly, or crazy. We'll deny them resources, even sabotage their progress and goals, and refuse to make effort for them like we do with those whom we are biased FOR.   

Whatever biases are common in a local community and culture, Narcissists will capitalize on. Some of them believe stereotypes and cultural prejudices are real, while sociopaths will use them in order to manipulate and oppress whether they believe them or not.

(Narcissists figure out quickly who's a** to kiss in order to get accepted and get ahead, and who it's okay to treat with disrespect because everyone else is bigoted against them or scapegoating them too. Many also seem to intuitively know that in each crowd there are different biases, so while in one crowd, everyone is biased against black men, in the next crowd everyone is biased against Hispanic women, and in the next it's white men, and in the next it's blond-ancestry women, and so on. A sociopathic Narcissist will morph into whatever crowd they're in, and find a way to be a member of the "in crowd" within that group, adapting the group's bully, bigot, and bias behaviors.)