There's a noticeable trend that the kids of this upcoming generation are ill-prepared for college and expect the authorities to protect them. In highschool, they're less likely to go out without their parents or work a part-time job (And on a positive note, less likely to drink or have premarital sex).
> For instance, Twenge argues that young people have become increasingly self-absorbed since the advent of the Internet. One piece of evidence she uses is a search she ran through Google's Ngram (which searches through printed books) for the phrase "I love me." She found a sharp spike in the phrase in the last few decades. But "I love me" sounds slightly off — surely most people say "I love myself." And lo, if you search "I love myself" (as I would guess Twenge did first), you find that the phrase fluctuated with much less satisfying results, and in fact occurred at a higher frequency in, for instance, the 1770s, than in the early 2000s. So, Twenge discovered a grammatical shift and disguised it as a cultural one.
> It's a small example, but the book is dizzying with this brand of deceptive spin.
I'm not arguing that the book is without merit, but I really don't think it comprehensively and inarguably states that the "younger generation" are as damaged as the "older generation" might suspect (and "the coming generation are wrong about all the things!" is a trope as old as time)
I think the main issue is that we're trying to measure changes over a long period of time across a wide swathe of people. Those are two very difficult areas to study.
And yes, we're better as a society at statistically mitigating the some of the consequences of intercourse, but that doesn't mean they don't exist, and that younger & unmarried folks are probably less prepared to deal with them, so there's a reasonable (although limited) general argument that less pre-marital sex among late adolescents is a turn towards more responsible or at least age-appropriate behavior.
There are other reasonable approaches to the topic as well.