Women of the 1920's started to behave in a different way. The acted rebellious. This act started the "new breed" of young Western women. These women were called "Flappers". Flappers behavior was considered outlandish. Something that is now ordinary to the 21st century. Flappers wore short skirts, bobbed their hair, and listened to jazz. Flappers were seen as brash for wearing makeup, drinking, treating sex in a casual manner, smoking, driving automobiles, and otherwise flouting social and sexual norms. The image of the flappers evolved, they were seen as independent young women who went by night to jazz clubs where they danced provocatively, smoked cigarettes and dated freely, perhaps indiscriminately. Flappers were active, drove cars, and openly drank alcohol, a defiant act in the American period of Prohibition.
Not only did women do all that but they also started to work outside their homes and challenging women's traditional societal roles. Flappers were considered a significant challenge to traditional Victorian gender roles, devotion to plain-living, hard work and religion. They also focused on consumerism and personal choice and were often described in terms of representing a "culture war" of old versus new. Not only that but flappers also advocated voting and women's rights. All these characteristics of the flappers is what has come to impact and shape the way women act now in the 21st century. Without the women of the 1920's making a great movement, it would not be acceptable or ordinary for women to act so "rebellious". It is not that women are rebellious, it is just that women wanted the same rights that men got, plus they wanted to be free from any ties of being labeled as a "traditional" woman.
The video below shows some picture examples of how women behaved.