Children can be trained to spot crucial cues on someone's emotional state, according to a recent study.

Researchers from the University of Lincoln found that children can learn to better recognize other people's emotions through games which emphasize the significance of the eyes and the mouth in conveying feelings.

"How we recognize and process facial expressions plays a big part in our social interaction skills," Petra Pollux, a cognitive neuroscientist from the University of Lincoln's School of Psychology, said in a statement. "We've all experienced walking into a room, looking around and immediately understanding that something has happened, and that's because we're reading the expressions on people's faces."

For the study, adults and 9-year-old children were shown images which conveyed varying levels of intensity of emotional expressions, from a small smile to a big grin, and asked to match it with the correct emotion. If they answered incorrectly, they were alerted by a tone.

Study participants were not given any instructions about eye-movements, but over the four sessions learned that focusing more on the eyes offered the crucial clues they needed.

The images used in the study were digitally manipulated and showed happy, sad or fearful expressions. An adult's ability to recognize emotions was also assessed and compared with children's, and in both cases, special eye tracking equipment was used to monitor their gaze pattern and determine which features of the face, such as the eyes, nose or mouth, they focused on most.

"It's really useful to know that the way a child scans a face plays an important role in recognizing emotions. This research could be used to develop mobile phone apps which turn this kind of training into a game," Pollux explained.

The findings, which were published in the peer reviewed science PLOS ONE, could lead to new or improved interventions for children and adults who have difficulty recognizing emotional states in others.