A new research study investigating the interpretation of facial expressions by individuals shows how cultural boundaries between them affects their psychology. Researchers found that while Americans tend to judge emotional status of a person by looking at the mouth, Japanese are likely to do so by looking into the eyes.

The research team led by Masaki Yuki, a behavioral scientist at Hokkaido University in Japan, confirmed the hypothesis using two studies - one using emoticons and one using manipulated photographs of real people.

In the first part of the study, Yuki and team presented a group of American and Japanese students with various computer-generated emoticons and asked them to rate on the basis of their emotional status - happy, sad or neutral.

They noted that while Japanese were likely to rate the emoticons by looking at the symbols representing eyes, their American counterparts tended to rate the emoticons on the basis of symbols depicting mouth.

For example, a majority of the Americans denoted the emoticons such as J as a happy face, whereas the emoticons L as a sad face. However, Japanese denoted the symbol (^-^) to indicate a happy face, and (; - ;) to indicate a sad (or crying) face.

Similar results were obtained in the second part of the study when researchers asked the students to interpret emotional expressions of computer manipulated photographs of real individuals.

According to Yuki, the research explained the impact of cultural differences on the psychology of individuals. Where Japanese tend to shy away from the public expression of their emotions and rarely use their mouth to express their feelings, in the U.S. overt emotional expression is the norm, he told LiveScience.com.

However, researchers concluded although eyes are considered a better conveyor of emotions, the results are consistent with obvious cultural differences which cause explicitly expressive Americans to consider mouth a better cue over eyes.