One of the benefits of a long marriage may be fewer arguments as the years go by, a new study finds.
 

Researchers at San Francisco State University report that as married couples grow older, they become more likely to handle disagreements by simply changing the subject.
 

The findings are in keeping with prior research showing that as people age, they avoid conflict in favor of more positive experiences, to try to make the best of their remaining years.
 

The new study included 127 long-time married couples in middle or old age who were followed for 13 years. They were videotaped during 15-minute talks centered on contentious topics ranging from housework to finances.
 

The researchers wanted to see if the couples' use of a common and harmful type of communication -- called the demand-withdraw pattern -- changed as they aged. In this pattern, one partner blames or pressures the other for change, while the other partner tries to avoid talking about the problem and withdraws from the discussion.
 

This type of avoidance generally is believed to cause damage to relationships because it prevents conflict resolution, and this may be particularly true for younger couples who may be dealing with issues that are newer to them.
 

Most aspects of demand-withdraw communication remained steady over time among the couples in the study, the researchers said, but with age both partners became more prone to changing the subject or diverting attention away from the argument.
 

The researchers reasoned that older couples have already had decades to voice their disagreements, so avoidance may be a way for them to move the conversation away from "toxic" areas and toward something more pleasant.
 

The age of the partners in a marriage appears to drive this shift in communication, but the change might also be influenced by the length of the relationship.
 

"It may not be an either/or question. It may be that both age and marital duration play a role in increased avoidance," study author Sarah Holley, an assistant professor of psychology and director of the university's Relationships, Emotion and Health Lab, said in a university news release.
 

In order to learn more about these influences, Holley hopes to compare older couples in long-term marriages with older newlywed couples.
 

Holley said demand-withdraw communication occurs in all kinds of couples. She compared heterosexual, gay and lesbian couples in a 2010 study and found "strong support for the idea that the partner who desires more change ... will be much more likely to occupy the demanding role, whereas the partner who desires less change -- and therefore may benefit from maintaining the status quo -- will be more likely to occupy the withdrawing role."
 

The study was published online July 1 in the Journal of Marriage and Family.