How did individual behavior suddenly go bad 50 years ago? I know that no external factors can ever explain individual decision-making, and especially individual

How did individual behavior suddenly go bad 50 years ago? I know that no external factors can ever explain individual decision-making, and especially individual responsibility, and that social and dietary "sciences" are delusions created by the spiritual adversary of rationality, but perhaps there is something we can meditate on to help us cope with the realization that people became intrinsically more sinful and flawed just a generation or two ago.