An interesting theory by Dr. Dave Owens is that people do not stand up in front of other people because they feel silly and are afraid to look bad. Therefore it is important to make people who stand up not feel bad.
It is a known fact that most women care deeply about how they look and would rather wear nice looking shoes that hurt them than comfortable shoes that look bad. For most men it's the other way around. Could this importance that women place on their looks, 100+ dollar haircuts, 500+ dollar dresses and makeup cabinets worth thousands be the biggest reason they are not as numerous in leadership positions as men?