If you think by examining someone's facial expressions you can judge if he has good or bad luck in the stock market, think again. A study published in the journal, Science, has shown that body language provides a better signal in judging whether the observed subject has just gone through an intensely positive or negative experience. To test highly intense faces, Dr. Hillel Aviezer and his colleagues presented test groups with photos of dozens of highly intense facial expressions in real-life situations. In one study, they compared emotional expressions of professional tennis players winning or losing a point. To discover exactly how people view images, the researchers showed different editions of the pictures to three groups of participants: 1 ) the full picture with the face and body;2) the body with the face removed; 3) the face with the body removed. Remarkably, participants could easily pick the losers from winners when they judged by the full picture or the body alone, but they only had a 50:50 chance of being right when judging by the face alone. Strangely, the participants .who viewed the full image believed that it was the face, not the body, that revealed the person's emotions. In an additional study, the researchers performed the same series of tests, asking viewers to examine a wider range of real-life intense faces. Again, viewers were unable to tell faces in positive situations from negative situations. The researchers also "planted" faces on bodies expressing positive or negative emotions. Sure enough, the researchers discovered that the emotion of the same face on different bodies was determined by the body on which it appeared. "These results show that when emotions become extremely intense, the difference between positive and negative facial expressions no longer seems clear," says Aviezer. "The findings challenge classic behavioral models, in which the boundary between positive and negative emotions is clear." Aviezer adds, "The results may help researchers understand how body and facial expressions interact during emotional situations. For example, individuals with autism  may fail to recognize facial expressions, but if trained to read important body language signs, their performance may significantly improve." What can we conclude from the study?
One cannot judge someone's emotions by facial expressions. The boundary between positive and negative emotions is clear. It's easier to tell positive emotions from negative ones if they're tenser. Body language is a better choice to judge intense emotions.