Highly mobile eyebrows that can be used to express a wide range of subtle emotions may have played a crucial role in human survival, a study suggests
The theory is that it evolved to transmit subtle semaphore signals of emotional states and empathy. This, in turn, is said to have helped prehistoric humans establish the large social networks needed for survival during the harsh last Ice Age.
Dr Penny Spikins, one of the researchers from the University of York, said: “While our sister species the Neanderthals were dying out, we were rapidly colonizing the globe and surviving in extreme environments.
Mobile eyebrows gave us the communication skills to establish large, social networks; in particular to express more nuanced emotions such as recognition and sympathy, allowing for greater understanding and cooperation between people.
The researchers compared the pronounced brow of early humans to the antlers on a stag – with more prominent features deemed a signal of dominance and aggression. But as relationship building became more important to survival, humans shifted towards a more expressive brow.
Prof O’Higgins added: “Sexually dimorphic display and social signalling is a convincing explanation for the jutting brows of our ancestors. The broader idea is that it is more important to express friendly emotions as we go through the time in human evolution, and increasingly important to get on better with people, through responding to vulnerability and being vulnerable’, Dr. Penny Spikins, one of the researchers from the University of York.