In our world today, there are many cultural “norms” that have been pushed by society starting at the top of leadership. Cultural norms tend to change as leadership pushes different ideas or beliefs or values from the top down.
Cultural norms are, in part, what make us different from other cultures. Most of these norms are taught to us by our parents. What’s appropriate in society etc. That’s why each generation has trouble fully understanding the two generations that have come after. Because different world events impact each generation for the good or the bad.