Most people can readily discern other people's emotions. I'll come right out and admit that I'm remarkably poor at this ability.
On the other hand, I can (badly) sing a number of 1980s cartoon theme songs from memory, so I suppose I got an even trade out of the universe. All right, maybe not, but who else do you know who can sing along with Transformers?
Getting back on topic, recognizing other people's emotions based on their facial expressions is very important for effectively interacting with others. Impaired emotional recognition is seen in a number of clinical disorders, such as autism.
Figuring out why some people have difficulty recognizing emotions may help find a way to correct the deficiency, or at least understand it. Along these lines, in the case of autism, recent research has shown that autistic children have impaired shadow recognition, possibly because they are drawn to and distracted by details (e.g. shadows) more readily than most people.
Certain kinds of brain damage, in which people became unable to either experience or recognize fear, suggests that emotional experience and recognition are linked. However, since no such study has been carried out on unimpaired individuals, and on a large scale, it's still an open question.
Tony Buchanan (Saint Louis University, United States) and coworkers have carried out a large-scale test of this hypothesis among the general population. They have found a link between emotional experience and recognition for happiness and fear, and have shown that this link is present even in 5-year-old children.
Testing the emotional link.
The scientists tested over 4500 people attending a traveling science exhibit in the United States, between June 2007 and July 2008. The exhibit was a demonstration of emotion that focused on fear.
The participants ranged from 5 years old to somewhere over 50, 60% of them female, and 62% Caucasian. Each participant was asked to make a face (based on standard psychological data sets) on a computer screen look as angry (or some other emotion) as possible by dragging a bar across the screen.
The sliding bar enabled the participant to morph the face along the full range of emotions (e.g. happy to sad), not just the emotion in question. The participants were scored based on how far away they dragged the sliding bar from the standard psychological facial experession corresponding with the emotion in question.
The participants were then instructed to think about how strongly (from very weak to very strong) they have ever felt the emotion in question. The tested emotions were surprise, fear, disgust, anger, and happiness.
A link between experiencing and recognizing fear and happiness.
The distribution of responses was centered on the standard (i.e. most accurate) facial expression, with the exception of disgust, possibly because the standard psychological facial expression of this emotion doesn't fit with common concepts of it. People who more intensely experienced either happiness or fear were statistically more likely to accurately identify it in the facial expressions of others.
Furthermore, people who less intensely experienced fear were less statistically likely to accurately identify that emotion than the other emotions. These trends were observed among all ages and both genders.
People who more (or less) intensely experienced fear were also somewhat statistically more (or less) likely to accurately identify surprise and happiness as well, but not anger. In contrast, a rigorous link between anger and surprise experience and recognition was not observed.
Implications.
Note that these scientists are not saying that experiencing happiness or fear causes recognition of the emotion. They are only saying that experience and recognition are correlated; for example, something related to both the experience and recognition of these emotions may be the unknown missing element.
There is a clear link between experiencing and recognizing fear and happiness (not anger or surprise), even among very young children. What this suggests is that if you haven't gone through these emotions yourself, you'll be less able to share or deal with them when they are experienced by those around you.
It's easy to understand how such an limitation would negatively affect someone's ability to interact with others. I hope this research is extended to more complex social phenomena, such as empathy, greed, and risk, with the goal of helping to understand such behaviors in normal and pathological settings.
for more information:
Buchanan, T. W., Bibas, D., & Adolphs, R. (2010). Associations between Feeling and Judging the Emotions of Happiness and Fear: Findings from a Large-Scale Field Experiment PLoS ONE, 5 (5) DOI: 10.1371/journal.pone.0010640