Languages have shaped our genetics in terms of physiological differences in speech.
The roof of the mouth, for instance, differs across cultures.
But language isn’t the only part of communication.
Facial expressions and mannerisms are a big part of communication, and the interpretation of these types of expression differs across cultures.
The facial musculature of humans is highly developed, far more so than in any other primate species.
As such, the lips and eyes reveal a lot about human emotion.
According to Herbert Gintis’ “Gene-culture coevolution and the nature of human sociality”:
“Humans have evolved a highly specialized and very costly complex of physiological characteristics that both presuppose and facilitate sophisticated aural and visual communication, whereas communication in other primates, lacking as they are in cumulative culture, goes little beyond simple calling and gesturing capacities.”
While other primate species’ may go “little beyond,” how far does ours go?
Prior studies have suggested that the evolutionary nature of facial expressions does not differ across cultures, but at least one study has found that expressions of happiness, anger, and sadness are perceived differently between the East and the West.
According to the study’s abstract:
“Briefly stated, the universality hypothesis claims that all humans communicate six basic internal emotional states (happy, surprise, fear, disgust, anger, and sad) using the same facial movements by virtue of their biological and evolutionary origins [Susskind JM, et al. (2008) Nat Neurosci 11:843–850].”
Looking at the way in which Western Caucasians and East Asians view various expressions according to their facial features, two groups – one of Caucasians and one of Chinese participants – were selected.
The study’s participants viewed emotion-neutral faces that were altered at random using technology. They were asked to classify the faces as happy, sad, angry, disgusted, fearful, or surprised.
Researchers were then able to identify the facial features that the groups of participants associated with the emotions.
From the responses, researchers deduced that Western Caucasians focused more on the mouth and eyebrows when identifying facial expressions, while Chinese participants focused primarily on the eyes.
These differences can lead to complexities in communication across cultures, resulting in misinterpretation or missed signals of emotional expression.
The findings support the concept of gene-culture coevolution and how culture is increasingly driving human behavior more than genetics.
We’ll talk more about cultural mannerisms and body language next week.