Not All Smiles Are Created Equal

"We think the reason why this happens is that being rejected is a very dangerous situation to be in," Bernstein said. "You're in a precarious state. You're without a group. From an evolutionary perspective, that's an extremely dangerous place to be."

Those who are rejected may be more careful about finding a new group to belong to and become more perceptive, Bernstein added.

Frank said the new study falls into a category of research that aims to understand human emotions.

"From a practical point of view, it has some implications for helping us understand why people make some of the choices they do, when they may seek out others, and when they may reject others, even if it may not be in their long-term interests to do so," he said.

The study was published in the October issue of the journal Psychological Science.

More information

For more on human emotions, visit the Argosy University.

SOURCES: Michael Bernstein, graduate student, Miami University, Oxford, Ohio; Mark Frank, Ph.D., director, Communication Science Center, University of Buffalo, N.Y.; October 2008 Psychological Science