A pair of Princeton psychology researchers has developed a computer program that allows scientists to analyze better than ever before what it is about certain human faces that makes them look either trustworthy or fearsome.

Research has uncovered that culture is a determining factor when interpreting facial emotions. The study reveals that in cultures where emotional control is the standard, such as Japan, focus is placed on the eyes to interpret emotions. Whereas in cultures where emotion is openly expressed, such as the United States, the focus is on the mouth to interpret emotion.