November 30, 2012
It’s Easier To Read Body Language Than Facial Expressions
April Flowers for redOrbit.com - Your Universe Online
Conventional wisdom, and current theoretical models, indicates that one can examine another's facial expressions to judge if they have just hit the jackpot or lost everything in the stock market. A new study, however, says this just isn't the way it works.
A research team from the Hebrew University of Jerusalem, New York University and Princeton University found that body language, rather than facial expressions, provides a better cue in trying to judge whether someone else has undergone a strong experience — positive or negative.
The team presents data showing that viewers in test groups were confounded when shown pictures of people who were undergoing real-life highly intense experiences. The study, published in the journal Science, reveals that when the viewers were asked to judge the emotional valences — positivity or negativity of the facial expressions - of the faces they were shown, their guesses fell within the realm of chance.
To test the perception of highly intense faces, the team presented test groups with photos of dozens of highly intense facial expressions in a variety of real-life situations, such as professional tennis players winning or losing a point. Such pictures are perfect for this type of study because the stakes in such games are extremely high from an economic and prestige perspective.
Dr. Hillel Aviezer of the Psychology Department of the Hebrew University and his colleagues, Dr. Yaacov Trope of New York University and Dr. Alexander Todorov of Princeton University, showed different versions of the same pictures to three groups of participants to pinpoint how people recognize such emotional valences. The first group saw the full picture with both face and body; the second group saw the body with the face removed; and the third group saw the face with the body removed. Although participants could easily tell winners from losers when they rated the full photo or the body alone, they were operating at chance level when rating just the face.
Participants in the full image — face and body — group were convinced it was the face that revealed the emotional impact, rather than the body. The research team calls this "illusory valence." They say it reflects the fact that the participants said they saw clear valence in what was objectively a non-diagnostic face.
In a related study, the team asked participants to view a broader range of real-life intense faces. This broader range included intense positive situations — joy (seeing one's house after a lavish makeover), pleasure (experiencing an orgasm), and victory (winning a critical tennis point) — and intense negative situations - grief (reacting at a funeral), pain (undergoing a nipple/naval piercing), and defeat (losing a critical tennis point).
The participants were again unable to distinguish between facial expressions of positive and negative situations. To test their theory even further, the researchers planted faces on bodies expressing the opposite positive or negative emotion. The participants determined the emotional valence of the same face on different bodies by the body, switching from positive to negative depending on the body with which they appeared.
"These results show that when emotions become extremely intense, the difference between positive and negative facial expression blurs," says Aviezer. "The findings, challenge classic behavioral models in neuroscience, social psychology and economics, in which the distinct poles of positive and negative valence do not converge."
Aviezer adds, "From a practical-clinical perspective, the results may help researchers understand how body/face expressions interact during emotional situations. For example, individuals with autism may fail to recognize facial expressions, but perhaps if trained to process important body cues, their performance may significantly improve."