Arguments over who does the washing up or mows the lawn are less likely to occur between seasoned spouses who have learned the art of conflict avoidance, research has shown.

A study of 127 middle-aged and older couples found that over time they grew less willing to risk having explosive rows.

Instead, they became more likely to adopt strategies such as changing the subject or keeping silent.

Such behaviour is normally seen as damaging to relationships because it leads to bottled up anger and resentment.

But for older couples, who have had decades to voice their disagreements, it might offer a way to keep the peace, say psychologists.

Scientists watched the progress of the married couples over 13 years and filmed 15 minute discussions between them, noting how they communicated.

In particular, the researchers were looking for evidence of "demand-withdraw" conversation patterns. This occurs when one person in a relationship is blamed or pressured by the other and responds by withdrawing or trying to avoid the issue.

Over the years, both husbands and wives increasingly demonstrated avoidance during conflict, said the researches whose findings are published in the Journal of Marriage and Family.

Both the age of the partners and the length of time they had been together probably contributed to the trend, said the researchers.

"It may not be an either-or question," said lead author Dr Sarah Holley, from San Francisco State University. "It may be that both age and marital duration play a role in increased avoidance."

She stressed that the "self-perpetuating and polarising nature" of demand-withdraw communication could be especially destructive in marriages.

If, for instance, a husband avoided his wife's demands to do housework, this could lead to an escalation of her demands and his withdrawal.

"This can lead to a polarisation between the two partners which can be very difficult to resolve and can take a major toll on relationship satisfaction," said Dr Holley.