Childhood is the most important human adaptation. If you don’t believe me, read this highly convincing essay.

But childhood is also one of the most diverse aspects of our shared human culture. You know the aphorisms that incorporate the phrase “Kids these days…” You also know that most of the time the utterance is foundationless, just a grumpy complaint by someone who doesn’t like the noise or disruption or some other annoyance that kids these days are so good at. But we also know that things really were different when we were kids, and that childhood varies wildly across the globe, culture by culture, nation by nation.

For example, when I was a kid, if first or second grade, I was out on the boat, by myself, using the five horsepower motor, as often as I could manage to pull the cord hard enough to get it started, which was in about one in five attempts. I walked home from Kindergarten and made myself lunch, using the stove and sometimes sharp knives. Today, I want my kindergartener to learn to use the stove and sharp knives, but I want him to do that after he moves out of my house!

Many American kids, these days, are Americans. Back when I was a kid, a lot of kids were ethnic-Americans, and I’m not talking about recent immigrants. After three or more generations, the Polish and Italian kids in my neighborhood were pretty much like all the other kids, but the households they lived in were internally similar but externally different. In those days, you could guess pretty well the ethnicity of each household by walking down the street just before dinner time and smelling the food. That, of course, is still true of modern day immigrant families, often, but it seems that these days, the first generation assimilates as fast as it can. And, in the really old days, long before my own memories, the rate of assimilation was even slower. There were entire regions of the US where the first language was not English, but something else, often German, for two or more generations. I think it is fair to say that the rate of assimilation has sped way up over the last generation or so.

Are American children different from children in other cultures? One might guess that they are, given that American themselves seem to be different. Of course, all cultures are different, and the difference between Americans and their kids vs., say, Indonesians and Iraqis may be much less than the difference between the people in the latter two cultures. One might also note that when diverse cultures around the world start to become more similar to each other, it is often (but not always, of course) because they are becoming Americanized. That seems to have been a phenomenon of the last few decades, but how much of a phenomenon was it, really, and is this global Americanization waning as the influence and even popularity of American culture wanes?

A new book, The End of American Childhood: A History of Parenting from Life on the Frontier to the Managed Child by Paula Fass, addresses many of these issues.

Historian Fass examines the history of American childhood and parenting since the days of the Founding Parents. For more recent times, she identifies a shift from self reliance and self-definition to a the age of helicopter parents, and asks how this shift ultimately changes American culture, for better or worse. She examines changes in the nature of assimilation, and explores what the science has to say about child development under changing cultural conditions. Mostly, Fass makes a set of claims that things today aren’t like they used to be in mostly bad ways, and urges parents to take a second look at their role in raising their children.

I’m agnostic as to whether or not I accept Fass’s charges and suggestions, but the book is a fantastic look at the history of American childhood, a story she often tells through fascinating examples of individuals living in times gone by, working in factories, running their farms, being adults in children’s bodies, and probably being less annoying and noisy than kids these days.

Fass also underscores the fact that children, and the growing-up process, is often, usually, overlooked by social historians.

Fass is a widely recognized scholar, Margaret Byrne Professor of History Emerita at the University of California at Berkeley, and Distinguished Scholar in Residence at Rutgers. She is a social historian by training, and also wrote Children of a New World: Society, Culture, and Globalization and several other books.