The Schwarz sons are now just completely high school in Rome. When the younger one is asked, "Do you feel American or Italian?", he answers "In Italy, I feel American. When we are in the States, I feel Italian."
The Schwarz sons are "third culture kids". Third Culture Kids are children who grow up away from their family's "home" country. Sociologists have found that third culture kids become both "a part of" and "apart from" their local environment, creating a "third culture" that does not wholly belong to either their "home" culture or the local culture where they live.
Third culture kids have their own particular issues that their parents have to watch out for. There are the obvious ones like ensuring that their child has a proper mother tongue. My daughter hears English from me, French from her father and Italian all around her. She's more or less trilingual. So which language is her mother tongue? (I'm trying to make sure that it's English!). How can I make sure that she is able to communicate in all three languages without rendering her not great in any language?
There are also more subtle issues facing third culture kids, relating to identity and the need of a "home". For a third culture kid, simple questions like, "Where are you from?" can require reflection. And often a third culture kids discovers, upon entering her passport country at age 16 to live (possibly for the first time in her life), that she knows a lot less about her "home" culture than she thought. She may have American parents, maybe even went to American schools overseas and speaks the English language like an American. But she realizes on "re-entry" that she doesn't like driving everywhere, she hates American food, it's too cold, she can't talk about anything with people and she doesn't understand why everyone dresses so badly.