A recent study found that marriages that begin in one’s early 20s are at a high risk for divorce. That might seem obvious—people who marry at, say, 19 are probably impulsive and don’t know themselves yet! But there is more to it than that. It’s not just horny 19-year-olds at risk. Even young “adults” (20 to 25) are at risk for divorce. Here are reasons why young marriages often come to an end.