To Have, to Hold, to Cherish and Annoy

As people age, their relationships with other people gradually become smoother except in one area—their marriages, a new study has found. Researchers discovered that the longer two people are married, the more likely they are to find each other irritating and demanding. It's completely normal—and could even be a sign of a healthy relationship, LiveScience reports.

"As we age and become more comfortable with one another, we're more able to express ourselves to each other," explained a researcher. The study quizzed adults of all ages about their relationships with spouses, family, and friends. The spousal relationship was rated the most negative in all age groups, although the older age groups, apparently more adept at avoiding confrontation, reported less conflict. (More marriage stories.)