Some of them do behave that way, but I believe that it is due to the environment that makes young adults children.
In Russia when I was growing up, you only have to have 8 years of compulsory education. Then you can start work at 14.
When I came to US I was appalled by infantilism of american young adults that are kept in schools until 18.
The good part is that people are waking up. I recently found that some of the american scholars share my view.
For example:
http://psychologytoday.com/articles/index.php?term=pto-4311.html RE: In every mammalian species, immediately upon reaching puberty, animals function as adults, often having offspring. We call our offspring "children" well past puberty. The trend started a hundred years ago and now extends childhood well into the 20s. The age at which Americans reach adulthood is increasing—30 is the new 20—and most Americans now believe a person isn't an adult until age 26.
The whole culture collaborates in artificially extending childhood, primarily through the school system and restrictions on labor. The two systems evolved together in the late 19th-century; the advocates of compulsory-education laws also pushed for child-labor laws, restricting the ways young people could work, in part to protect them from the abuses of the new factories. The juvenile justice system came into being at the same time. All of these systems isolate teens from adults, often in problematic ways.
The Case Against Adolescence: Rediscovering the Adult in Every Teen
ISBN-10: 188495670X
Hardcover: 450 pages
Editorial Reviews
Review
Perhaps it is time for a paradigm shift in how we understand the tumultuous time we call adolescence. Dr. Epstein s landmark book may be just what we need to help enhance our understanding of and better serve those moving through this complex period of life. --Drew Pinsky, M.D., Co-Host, Loveline ; medical director, Department of Chemical
Review
This is a profoundly important book. Dr. Epstein is raising issues about our young people that we need to think about and evaluate carefully. Generally, I think the institutions that serve our young are sound, but this book points to some obvious problems most especially the fact that our young people are largely isolated from the adult world. If you care about America s young, this is a must read. --Dr. Joyce Brothers, author & columnist