Gender Bias is a discrimination that often goes unnoticed on a day to day basis. This Bias has been push through each generation from early history when all women would stay at home to care for the family and house while the man went to work to provide the income for the family. For history to have a period of time like that creates a bunch of stereotypes for what boy and girl should be and act like from an early age. It was up until the nineteenth century when women were allowed to partake social life, education, and politics.
These ideas where pushed through movements like Christianity and the age of enlightenment. It has taken women movements and acts from the government for women to be respected by institutions of the government. Although women are still fighting to this present day to still have equality between men and women. Our history allows us to see there has always been separation of fair equality between men and women. Overall both of these links below talk about gender bias in different and similar ways but both educate you on gender bias in the world today. They both also touch on how gender bias has progressed over the years and through movements.
https://www.huffingtonpost.com/lisa-marie-jenkins/unconscious-gender-bias-e_b_7447524.html