Gender bias is faced are due to the male dominance thinking of society, even women own self do not believe in women achievement and comment her.
Basically what that made is: lack of self confident which more and more depend on this society thinking, perception. But Educated peoples must have change the thinking about equality, but not, you know why ;because there parents told daughter to not to talk with other, not to go night outside, not to fulfill in the name of boundary of society/restriction . on the other hand they do not say their son about the same things, that do not make someone girl hurt, do not use girl for your need, do not abused them even with his sister parent do not slap in the face of his son when he start abuse, humiliate, command his sister either she is young or old. In the mean time she start to live in society thinking where male is superior than women observing his brother/father behaviour. Because of all of these girls are always in boundary/restriction that make they skeptic, anxious , nervous instead of bold, confident and commanding.
To those how do not understand women or think that they are only fit like caring and kitchen jobs that are worthless. ohh men try just 1 week to be your mom/wife/sister do whatever she do just one week and you will know difficult and how calmness task needed.Start to eliminate gender biased from our family world it self free from it.
Now i would like to say something more about girl Intelligent, I heard one single line from my old grandpa a great saying " women are more powerful than men but they are always driven by shyness." How this say about intelligent is if you r shy/fearful either you boy or girl your less likely to sucess in life.
Special thanks to @cabernet from her post i got attention to about this topic