Research psychologist Jeffrey Arnett says these terms can suggest that many Americans 43 20-somethings. He says, "There's a tendency at least in the United States for people to look at this negatively and to deplore it and say what's wrong with them that they won't grow up?" He calls th e 20s a "special decade of life." He says Americans should consider the positive aspects. For example, 20-somethings us ually have a series of school and work experiences. They may have several serious romantic relationships. Or they might try living in different cities or even different countries.