They may not signal financial independence as often as they did in the past. Our expectations usually lag behind cultural changes. New standards of economics and education in the U.S. certainly hint that new timetables will emerge. And divorce statistics indicate that any married person may need a safety net at some time. But even if parents acknowledge those conditions in society, they still may not expect their kids to return home.
Statistics indicate the possibility is higher than parents think.
We like predictability. In our Life Course Perspective we expect gradual change punctuated only occasionally with big events like graduations and births of babies. Often, we assume that our experience will be repeated by the next generation, as if the Life Course is a standard path that everyone will follow. The result is a set of expectations that fits the parent generation very well, but doesn't at all describe the younger generation. For parents to form realistic expectations about boomerang kids, they will have to think more about the societal conditions for today's young adults and less about their own experience a generation ago.