Women working is not necessarily the cause. It fits the criteria of a symptom.
What do you think is the root cause?
It's sometimes difficult to exactly time the onset of a particular item, and thus to unambiguously establish whether it was a "cause" or a "result" (i.e., "symptom"). Below my tentative list of "factors":
1. The Pill
2. Urbanization/mobility and less community policing
3. The demographic bulge
4. Countercultural ideology
5. Economic optimism / prosperity
6. Weakening of traditional institutions
7. Vietnam War pressures
8. Mass media + music culture
9. Shifts in parental authority
10. Peer group norm diffusion
11. Automobile culture / mobility
12. Decline of early marriage norms
13. Growth of co ed environments
14. Changing gender roles (including delayed marriage and longer female workforce participation; conversely: increasing female college enrollment)
15. Secularization trends
16. Legal changes (e.g., privacy, contraception access)
17. Postwar psychological shifts (optimism, individualism)
18. Anti establishment political climate
19. Popularization of therapy / self expression
20. Influence of European avant garde ideas
21. Rise of youth consumer culture
22. Technological changes (cars, phones, records)
23. Expansion of leisure time
24. Geographic mobility / interstate migration
Regards,