I think you have to look at the parents. Teenagers in 1990 were born around 1975, so their parents were born around 1945. (I'm not sure what the average age was

I think you have to look at the parents. Teenagers in 1990 were born around 1975, so their parents were born around 1945. (I'm not sure what the average age was when people had kids back then, but the ballpark should be right.) For 90s and early 2000 teenagers, the parents were born post WW2, and had their formative teen or twenties years in the very liberal late 60s and early 70s. They experienced the shift from black pedagogy and strict morals to anti-authoritarian and liberal norms. They grew up in an opening and progressing society. I could imagine they passed on a certain optimism and openness to their children. Contrast with the later generation, whose parents grew up in the Reagan and Thatcher times (keyword "no future"). I imagine those parents would be more pessimistic and protective on average. I was born in 1984 and certainly my parents had that optimistic outlook ("ones kids are going to have it at least 50% better as their parents" was a widespread idea at that time). And I had a lot of freedom growing up that kids in the 2000s didn't have. Growing up in the somewhat optimistic 90s, I hope that my generation is going to be a "good" parent generation again...