Home People Evolution and Body Language

Evolution and Body Language

Photo: pixy.org

What Signalling in the Animal World Tells Us About Posture

As far as human history is concerned, city living is a recent development. And the boardroom? That’s even newer still.

Israeli historian Yuval Noah Harari wrote in Sapiens (Harper 2011) that the basic unit of society for about 70,000 years was that of family – or the tribe. Yes, our sapiens ancestors lived in small hunter-gatherer bands. Then, later, villages. In Sapiens and his follow-up Homo Deus, Harari makes the distinction between “objective needs” and “subjective needs.”

Many behaviors that were conducive to survival and reproduction 70,000 years ago are no longer needed. Farm animals provide an example: they are separated from their young, and kept in isolation. Kinship and socialization are no longer required for physical survival.

The misalignment of what animals project and what they need is the underpinning thesis of evolutionary psychology. Today, the display of hardwired biology accompanies learned behavior in the form of “signalling.” 

In his book The Fall of the Third Chimpanzee, American geographer Jared Diamond describes the display known as “stotting” among quadrupeds such as the gazelle. Stotting is when an animal springs into the air, increasing its visibility to predators. In doing so, the gazelle is touting its own superiority; it can afford to be seen and be chased.

Among humans, many gestures and postures are biologically hardwired. The origin of head-shaking is breastfeeding. Flaring of ones nostrils, often done unconsciously, allows more air to oxygenate the blood, forecasting a “fight or flight” response. Smiling in non-human primates is a sign of aggression, though in people it is typically submissive. 

Crossed arms are almost universally interpreted as representing insecurity and defensiveness. It is a protective stance, guarding organs and shielding an attack. By contrast, a posture such as placing hands on one’s head presents an open rib cage and abdomen. This signals comfort and security. 

While many gestures are learned, it is always worth considering how objective origins of body language play out in today’s society. The animal world tells us much about our own posture.