Gender is a social construction of ideas that defines the roles, belief systems and attitudes, images, values and expectations of men and women. It contributes heavily to power relationships , not only between men and women, but also within each group, and this results in many social problems. Different cultures have different ideas about gender, about what is suitable for men and women to do and to be. Gender not only changes from culture to culture. It also may change over time, or it may change within a culture during a crisis situation.