Something about that period of shared vulnerability enabled the forming of a deep bond among new moms. But as our kids got older, people moved away, our kids preferred some kids over others and our lives got busier with the birth of other children. Gradually, we lost that connection. And that support.
So far as the tendency to be overinvolved and overwhelmed with school and social life, I don't suspect that teenagers today are fundamentally different than those from 10 or 20 years ago -- too much pressure on a foundation has always resulted in cracks. Yet, I suspect there are at least two cultural changes that do make teens today feel these pressures more acutely.