First, most people suffer from what psychologists call “the transparency illusion”—the belief that what they feel, desire, and intend is crystal clear to others, even though they have done very little to communicate clearly what is going on inside their minds.
Because the perceived assume they are transparent, they might not spend the time or effort to be as clear and forthcoming about their intentions or emotional states as they could be, giving the perceiver very little information with which to make an accurate judgment.

“Chances are,” Halvorson writes, “how you look when you are slightly frustrated isn’t all that different from how you look when you are a little concerned, confused, disappointed, or nervous. Your ‘I’m kind of hurt by what you just said’ face probably looks an awful lot like your ‘I’m not at all hurt by what you just said’ face. And the majority of times that you’ve said to yourself, ‘I made my intentions clear,’ or ‘He knows what I meant,’ you didn’t and he doesn’t.”

One person may think, for example, that by offering help to a colleague, she is coming across as generous. But her colleague may interpret her offer as a lack of faith in his abilities. Just as he misunderstands her, she misunderstands him: She offered him help because she thought he was overworked and stressed. He has, after all, been showing up early to work and going home late every day. But that’s not why he’s keeping strange hours; he just works best when the office is less crowded.

“If you want to solve the problem of perception,” Halverson says, “it’s much more practical for you to decide to be a good sender of signals than to hope that the perceiver is going to go into phase two of perception. It’s not realistic to expect people to go to that effort. Can you imagine how exhausting it would be to weigh every possible motivation of another person? Plus, you can’t control what’s going on inside of another person’s mind, but you can control how you come across.”

People who are easy to judge—people who send clear signals to others, as Halvorson suggests people do—are, researchers have found, ultimately happier and more satisfied with their relationships, careers, and lives than those who are more difficult to read. It’s easy to understand why: Feeling understood is a basic human need. When people satisfy that need, they feel more at peace with themselves and with the people around them, who see them closer to how they see themselves.

Emily Esfahani Smith with refernce to the book of  Heidi Grant Halvorson

To read the whole article: http://www.theatlantic.com/health/archive/2015/04/mixed-signals-why-people-misunderstand-each-other/391053/