Darwin was wrong: facial expressions of emotion aren't universal, say scientists at the University of Glasgow.
In his 1872 book The Expression of the Emotions in Man and Animals, Darwin argued that people from different cultures express the same state of mind by the same facial movements.
But the Scottish team has tested this by using a new, sophisticated computer graphics platform, modelling four-dimensional mental representations of six basic facial expressions in two cultures.
Fifteen Western Caucasian and 15 East Asian subjects were selected to view 4,800 animated 3D images of faces exhibiting randomly generated facial movements.
They categorised each animation according to the six basic emotions and rated the intensity of the emotion perceived.
And the results showed that while Westerners represent each of the six basic emotions with a distinct set of facial movements common to the group, Easterners do not. Furthermore, East Asians represent emotional intensity with distinctive early eye activity whereas Westerners use other face features.
"Our results show that facial expressions of emotion are culture-specific, refuting the notion that human emotion is universally represented by the same set of six distinct facial expressions," says lead researcher Rachael Jack.
“For Western Caucasian, there do indeed appear to be six basic facial expressions of emotion, but the same is not true for East Asians.
According to Jack, while expressions of fear and disgust originally served as an adaptive function in early humans, they have since evolved and diversified.
"Our data highlights the powerful influence of culture on shaping basic behaviours once considered biologically hardwired," she says.