"Emerging Adult"

I can't help thinking of larvae, pupae, bugs.

This term, "emerging adult," coined by Jeffrey Arnett, refers to folks between the ages of 18-29, people who haven't quite found themselves, who are perhaps still on the parental dole, who have every intention of becoming an adult but have thus far failed to make the cut.

The Cut - a matter of definition, I suppose.  What exactly constitutes an "adult?"

My daughter was once an "emerging adult," but when she made the conscious decision to have a baby, she grew up, or rather hatched.