Human facial expressions communicate complex emotion information

There are more than 7bn people on the planet, and each of them has their own unique face. The sum of a person's eyes, nose, cheeks and mouth all individual to them. And now, new research shows that the emotion information transmitted by facial expressions appears to be just as diverse, rich, and complex as the faces themselves. From happiness to sadness, fear to anger, human facial expressions can communicate myriad emotion messages, and without the need for words. But until now, scientists have not fully understood how something as simple as a raised brow or an upturned lip can communicate such complex emotion information. The new study, led by the University of Glasgow and published in Current Biology, has investigated how facial expressions can communicate complex combinations of broad and specific emotion information. Researchers found that different facial movements such as a lowered brow or gaping mouth can jointly communicate both broad and specific emotion information as multiplexed signals-i.e., those that can convey two types of information.