CHANCES are that in the last week someone has irritated you by standing too close, talking too loud or making eye contact for too long. They have offended you with the high-pitched shrill emanating from the earphones of their iPod or by spreading their legs unnecessarily wide on a packed subway car.

But what makes you feel hostile toward “close talkers,” as the show “Seinfeld” dubbed people who get within necking distance of you when they speak? Or toward strangers who stand very near to you on line? Or toward people who take the bathroom stall next to yours when every other one is available?

Communications scholars began studying personal space and people’s perception of it decades ago, in a field known as proxemics. But with the population in the United States climbing above 300 million, urban corridors becoming denser and people with wealth searching for new ways to separate themselves from the masses, interest in the issue of personal space — that invisible force field around your body — is intensifying.

Scientists who say Americans share patterns of movement and behaviors to protect their personal space have recently found new evidence in a cyber game.