London, Jan 22 (Agencies): Do you feel that your spouse doesn't comprehend you? It may be because you are too close to each other, scientists say.

Psychologists at the University of Chicago and Williams College in Massachusetts found that when two people know each other too well they assume they share too much knowledge and their language becomes dangerously ambiguous.

This "closeness communication bias" can lead to long term misunderstandings, rows and even relationship problems, they said.

The researchers found that often couples and good friends communicate with each other no better than they do with strangers. Sometimes they are clearer with strangers because they assume no common knowledge.

This is a dangerous phenomenon which could cause marital discords, warned Prof Boaz Keysar, the co-author of the study.

"People commonly believe that they communicate better with close friends than with strangers," Prof Keysar was quoted as saying by The Telegraph.

"That closeness can lead people to overestimate how well they communicate. Your language can become so ambiguous. The brain becomes lazy," he said.

To prove their theory, Prof Keysar and his team recruited 24 married couples. The spouses sat in chairs with their backs to each other and tried to discern the meaning of each other's ambiguous phrases.

The researchers used common phrases to see if the spouses were better at understanding phrases from their partners than from people they did not know.

It was also found that spouses consistently overestimated their ability to communicate, and did so more with their partners than with strangers.

Prof Kenneth Savitsky said: "A wife who says to her husband, 'it's getting hot in here,' as a hint for her husband to turn up the air conditioning a notch, may be surprised when he interprets her statement as a coy, amorous advance instead.

"Some couples may indeed be on the same wavelength, but maybe not as much as they think. You get rushed and preoccupied, and you stop taking the perspective of the other person, precisely because the two of you are so close."

A similar experiment with 60 Williams College students showed that the phenomenon also applies to close friends.

"Our problem in communicating with friends and spouses is that we have an illusion of insight. Getting close to someone appears to create the illusion of understanding more than actual understanding," said co-author Prof Nicholas Epley.

That's why, Prof Savitsky added, it's always important to bear in mind the point of view of others – no matter how close to them you are.

The study is published in the journal of Experimental Social Psychology.