It's often said that seeing is believing. But, a new study says that believing is seeing too -- when it comes to perceiving other people's emotions.
An international team has carried out the study and found that people see facial expressions based on what they expect to see -- a pattern that can lead to trouble, the latest issue of the 'Psychological Science' journal reported.
In fact, researchers have found that the way people initially think about the emotions of others biases their subsequent perception and memory of their facial expressions.
Co-author Prof Jamin Halberstadt of the University of Otago said: "So once we interpret an ambiguous or neutral look as angry or happy, we later remember and actually see it as such.
"We imagine our emotional expressions as unambiguous ways of communicating how we are feeling, but in real social interactions, facial expressions are blends of multiple emotions -- they are open to interpretation.
"This means that two people can have different recollections about the same emotional episode, yet both be correct about what they 'saw'. Emotion perception is a paradox. It turns out the more we seek meaning in others' emotions, the less accurate we are in remembering them."
In the study, the researchers showed experimental participants still photographs of faces morphed by computer to express ambiguous emotion and instructed them to think of these faces as either angry or happy.
Participants then watched movies of the faces slowly changing expression, from angry to happy, and were asked to find the photograph they had originally seen. People's initial interpretations influenced their memories: Faces initially interpreted as angry were remembered as expressing more anger than faces initially interpreted as happy.
By measuring subtle electrical signals coming from the muscles that control facial expressions, the researchers discovered that the participants imitated on their own faces the previously interpreted emotion when viewing the ambiguous faces again.
"In other words, when viewing a facial expression they had once thought about as angry, people expressed more anger themselves than did people viewing the same face if they had initially interpreted it as happy," Halberstadt said.