A recent investigation has revealed that human beings can configure their faces in thousands of ways to convey emotions, but only 35 expressions are valid to transmit these sensations in all cultures. In addition, the number of ways in which our faces can express each emotion varies.
So, while the disgust and disgust, for example, only need a facial expression to be understood throughout the world happiness has 17, which shows the many varied forms of joy, delight and satisfaction, according to the authors of the study of the Ohio State University (United States). "It was a pleasure to discover – admitted Aleix Martínez, cognitive scientist, professor of electrical engineering and computer science and co-author of the study – because he talks about the complex nature of happiness."
The study found that differences in how our faces convey happiness can be as simple as the size of our smiles or the wrinkles near our eyes. He also discovered that people use three expressions to express fear, four to express surprise and five to express sadness and anger"Happiness acts as a social glue and needs the complexity of different facial expressions, disgust is just that: disgust", explains Martinez.
The findings of this research, published in the journal 'IEEE Transactions on Afective Computing', are based on Martinez's previous work on facial expressions, which found that people can correctly identify other people's emotions about 75 percent of the time based solely on subtle changes in the way blood flows colors a person's nose, eyebrows, cheeks or chin.
In this study, Martínez and his co-author Ramprakash Srinivasan, a doctoral student in Martínez's laboratory, They put together a list of words that describe feelings: 821 words in English, specifically. Then they used those words to search the Internet to get images of people's faces. Professional translators translated those words into Spanish, Mandarin Chinese, Farsi and Russian. To avoid bias, they used each word to download an equal number of images.
They connected the words to popular search engines in 31 countries in North America, South America, Europe, Asia and Australia, and ended with approximately 7.2 million images of facial expressions in a variety of cultures. The study did not include countries from the African continent or other remote parts of the world due to the limited number of images available from those areas.
Psychologists have debated how to classify human emotions for centuries. An ancient Chinese text, dating from the year 213 a. C., and then modified over the years, described seven "feelings of men" as joy, anger, sadness, fear, love, displeasure and liking.
Martinez, whose research interests intersect with both engineering and human brain behavior, thought there had to be more than seven or eight. "To think that humans are only capable of eight emotions is absurd," he said, "we are complex creatures, what about the different forms of joy?" We experience the world at a much deeper level than just eight emotions."
Martinez and Srinivasan hoped to identify the facial configurations that convey emotion across cultures. Based on computer algorithms, they found that the human face is able to configure itself in 16,384 unique ways, combining different muscles in different ways. They took the 7.2 million images that their searches produced and classified them into categories, looking for those that expressed emotions in different cultures. Martinez thought they would find at least a few hundred but only found 35. "We were shocked," Martinez admits, "I thought there would be many, many more."
Since the number of universal expressions was smaller than expected, they wondered if most expressions of emotion were specific to each culture. The result of this study surprised them even more. The analysis of the same data set of 7.2 million images showed that there are only eight expressions that are used in some cultures but not in all. These eight expressions convey positive and negative affect, but not categories of emotion such as joy and anger. The researchers concluded that most facial expressions of emotion are universal, that there are only a few dozen of them and that a large number of them are used to express joy.