A team of Spanish and Brazilian researchers has looked at how well—and how quickly—we can recognize the facial expressions of others. Correctly recognizing the emotions behind these expressions is important because they act as signals, and we make judgments and deductions about other people based on what we see. "These inferences can strongly influence election results or the sentences given in trials, and have been studied before in fields such as criminology and the pseudoscience of physiognomy, " explains University of Barcelona psychologist Jose Antonio Aznar Casanova, who worked on the study.
When the researchers gave a group of psychology students 0.1 seconds to look at a face, they found that they could detect happiness better and faster than sadness. "Positive expressions, or expressions of approach, are perceived more quickly and more precisely than negative, or withdrawal, ones," Aznar Casanova says. "So happiness and surprise are processed faster than sadness and fear."