Everybody has their own prejudice. The pattern in which women are depicted in history suggests how people may bring bias to their work. Our brains tend to form associations in order to process faster, and some bias is formed within the process. When people are aware of some of their bias, some are left unnoticed. An easy self-assessment technique is to use the Implicit Association Test (IAT) Being aware of having a bias is the first step in changing it.
Confirmation bias refers to the tendency for human beings to gather evidence to prove their views and ignore contrasting information. When some historians were examining those women in power, they may unconsciously present more negative information than achievements due to their implicit bias toward women. People should keep an open mind about having a bias. It is critical to admit that we have our own bias and consciously adjust it. And when we are finding information, it is also important to keep the confirmation bias in mind and try our best to reach objectiveness.