Dustin Dwyer

Using data on surnames dating back almost 1,000 years, economic historian Gregory Clark says he's found evidence that families rise and fall across generations at a much slower rate than anyone previously thought. And he says that rate remains constant across national boundaries and time periods.

Clark is writing a book about his research, and he says he's still working out some of his conclusions, but here are six possible takeaways from what he's found so far:

Here is a question that social scientists have been pondering for years: How much of your success in life is tied to your parents, and how much do you control?

The academic term used for this is "social mobility." And a striking new finding from economic historian Gregory Clark of the University of California, Davis claims your success in life may actually be determined by ancestors who lived hundreds of years ago. That means improving opportunities across generations might be a lot harder than anyone imagined.