Just as an Irish brogue or a Minnesota lilt betrays one's background, facial expressions and body language can also reveal our cultural origins. According to new research, such “nonverbal accents” also provoke stereotyped perceptions of others' personalities.

Many researchers regard nonverbal behavior to be a universal language—wherever you go, a smile looks like a smile. But a growing body of research suggests that where we hang our hats shapes both how we display emotion and how we perceive it in others. In a new study, psychologists Abigail Marsh, Hillary Elfenbein and Nalini Ambady, all then at Harvard University, found that American volunteers could distinguish American from Australian faces when the faces were photographed smiling but not when they were photographed with neutral expressions.

In addition, the way Americans and Australians walked or waved in greeting not only telegraphed their nationality but also triggered prevailing stereotypes about the two groups: Americans were judged more dominant (think, “Carry a big stick”) and Australians more likable (think, “G'day, mate!”).

A different study, led by psychologist Masaki Yuki of Hokkaido University in Japan, suggests that people from different cultures are attuned to different nonverbal cues. The group found that Americans, who tend to express emotion overtly, look to the mouth to interpret others' true feelings. Japanese, who tend to be more emotionally guarded, give greater weight to the eyes, which are less easily controlled.

“These studies show both that people can be sensitive to cultural cues that they are barely aware of and also that their own cultural norms can lead them astray,” comments Judith Hall, who studies nonverbal communication at Northeastern University. For example, “Americans who think the Japanese are unexpressive mistake subtlety for lack of expression. These Americans would misjudge facial cues that Japanese might be very successful at interpreting.”

Such misjudgments can have unintended consequences, Marsh argues. “Everyone knows how spoken communication breakdowns can lead to cross-cultural misunderstandings,” she says. “These studies highlight the importance of nonverbal communication as well. Improving awareness of these differences might go a long way toward improving cross-cultural interactions.”