According to Medical Xpress, if you try to see happiness in the facial expressions of others it can reduce your aggressiveness.
Professors Marcus Munafo and Ian Penton-Voak, from the University of Bristol, delved into the relationship between the recognition of emotions in ambiguous facial expressions and aggressive thoughts and behavior. They looked at healthy adults and at high-risk adolescents (for committing a crime).
What was the result of the study, published in the journal of Psychological Sciences?
The researchers found that they could modify a person’s bias in emotion recognition and encourage them to see Happiness by showing participants composite images of happy, angry or emotionally ambiguous facial expressions and then asking them to rate them as happy or angry, which allowed the researchers to establish a baseline for how likely a participant was to see an ambiguous face as angry.
Professors Munafo and Penton-Voak then used the results to encourage some of the participants away from this negativity bias by telling them that some of the ambiguous faces they had previously labelled as angry were in fact happy.