A science blogger examines pronouncements of cultural decline:
Taken together, these various indicators — what percentage of teenagers have had "many" partners, what percentage has ever had sex, and what percentage has a common STD — all argue for a period of cultural decline starting in the 1960s, perhaps as early as the late 1950s, which lasted until about 1990. Since then, however, our culture has been in a state of progress regarding teenage sluttiness. Thus, if any age cohort gets to brag about improving sexual mores, it is those born about 1975 or after.
The Dish 