- Many major cities around the world have large populations of immigrants who have come from other countries. Adapting to life in a new place forces people to seek out new friends, face new problems, and often learn a new language.
- As people are living longer in the US, more middle-aged adults are becoming caretakers of aging parents who can no longer care for themselves. This role of "parent sitter" involves caring for parents similarly to how they cared for their own children.
- The US is becoming a non-smoking society as hundreds of cities and some entire states pass laws restricting the sale and use of cigarettes. Many private companies have also implemented policies restricting or prohibiting smoking by employees.