How does american culture define "femininity" and "masculinity?" are these definitions universal, or do masculine and feminine ideals vary from place to place and over time?

Feminine--caring, nurturing, compassionate, soft spoken, cooperative, focused on appearance, dainty.

Masculine--aggressive, tough, strong, leader, commanding, and risk-takers.

The gender expectations are universal, but the expectations themselves vary across time and place. Margaret Mead's research of New Guinea is an example of how a small area can have varying gender expectations from tribe to tribe. Gender is constructed by society and therefore changes based on culture.