Prior to the 70s it was believed that people were either male or female, black and white. Masculinity or Femininity were on a continuum and on opposite sides of that continuum. This means that if you were born as a man then you would want to be as far to the masculine side as possible to be deemed healthy. While women should be as feminine as possible.
In 1937 Anne Constantinople claimed that masculinity and femininity are instead on two separate scales, low or high femininity and masculinity. This means that a man could love to go hunting play sports and still enjoy being home with the family and cooking.
This brings up an interesting point of our characters. Do they generally exhibit societies expectations of how they should act or do they go against societies expectations? Do we put our characters into roles that society expects them to be in or are we breaking society norms?
In my society there are expectations for males and females and when they break those expectations they are punished in some way. This needs to also happen in our books with our characters when they break the expectations of society.
Another interesting point is how are our characters internalizing those expectations? Is it affecting them to be going against the expectations of society? How do they view others who go against societies norms and expectations?
TidBit: Going along with going against societies expectations. When going to school for undergrad I would often stay home and take on the traditional feminine roles such as taking care of kids cooking cleaning etc.... While my wife would go to work to pay the bills. This worked for us but I always felt the pressure of not working and of my wife working.