Do marriage and parenthood make people more conservative about women and families?
That raises an alternative possibility. Maybe the difference between under-30s and their elders isn’t the era in which they grew up. Maybe it’s a lack of life experience. As young people pass from their 20s to their 30s, they get married and have kids. They lose their naïvete about self-realization, having it all, the equality of family structures, and the interchangeability of moms and dads. According to this theory, the reason why older people are more likely to believe that unwed motherhood is a big problem, or that kids do better with stay-at-home moms, is that beyond the age of 30, you discover that these things are true.
IOW, the older you get, the smarter your parents get and the dumber your professors get.
As an aside, Steve Sailer has noted that there is around a steady 0.9 correlation coefficient (i.e. extremely strong correlation) between the combined demographic factors of the average number of children a white woman has slash the average number of total years white women between 18 and 44 are married (most possible being 27 years) in a given state, and the percentage of vote Republican Party Presidential candidates get in that state. What it means is that the GOP is the party of traditional nuclear white families, while the Democrats are the party of everyone else.