An unchallenged assumption in individualistic Western nations is that is good and is bad.

individualism; conformity

Explanation:

         David Guy Myers is a well known psychologist in the Hope College, United States of America. He has conducted several experiments on psychology test on human behavior.

         According to him, in the Western region of the world, the unchallenged assumption of the people is that they assume or they believe that conformity is bad where as individualism is bad.

         Conformity may be defined as the change in belief or its behavior to please or accord with other people.

this is a pretty broad question and can be a pretty lengthy answer. since 1900, women have gained a lot more rights and have become active in the workforce. with women being in the workforce, men play a larger role in family life. many family tasks are shared between men and women, whereas, women used to be the sole family caretakers.

that should get you started at least.