Social scientists who have studied social and cultural trends and public opinion, like psychologist Daniel Yankelovich, have been interested in the change in personality traits between those born before about 1940 and the Baby Boomers. Remember that the Baby Boomers were called the Me Generation. That a large difference exists between the Baby Boomers and their children, and those older generations born before about 1940 is not just a theory.
Yankelovitch wrote The new morality: a profile of American youth in the 70's, 1974.
He wrote New rules, searching for self-fulfillment in a world turned upside down, 1981.
Historian Christopher Lasch wrote The Culture of Narcissism: American Life In An Age of Diminishing Expectations, 1978. Both social scientists offer evidence of a fulfillment of II Timothy 3: 1-4, though they do not get into Biblical prophecy. And talking about a fulfillment of II Timothy 3: 1-4 may be theologically incorrect in many churches.