I spent a couple years studying non-verbal communication in gorillas, so to read news that there’s some breakthroughs in our understandings handedness and communication in apes made me extremely excited. The news originates from Gillian Sebestyen-Forrester‘s latest paper in the journal Animal Behaviour, “A multidimensional approach to investigations of behaviour: revealing structure in animal communication signals.”
Sebestyen-Forrester observed that a right-handed bias for actions that also involved head and mouth movements among gorillas. As you may know, the right side of the body is controlled by the left hemisphere of the brain, which is also the location for language development. Sebestyen-Forrester’s hypothesis is that this handedness bias offers major clues as to how language developed in humans. Gorillas deploy a wide range of non-verbal communicative behaviors, such as facial expression, eye gazes and manual gestures, and tactile signals (like grooming and huddling which are used for social cohesion). In my own experiences, I quickly came to learn what a lip-smack, pursed lip, chestslap, purr, etc. meant.
But I digress, Sebestyen-Forrester tested her hypothesis by recording the behaviors of a female gorilla mother and her infant, along with their social network at the Port Lympne Wild Animal Park in Kent, United Kingdom. She coded the results and noted that behaviors that involved head and mouth movements correlated with right handedness.
This multidimensional method evaluates all synchronous physical actions of the body in a reciprocal manner. And her analysis did reveal a coordinated physical action, thus demonstrating differences in lateral motor activity. She understands this observation to be ethologically valid to extend that animals with the closest genetic link to humans would express communication skills with some similarities to human.
- G FORRESTER (2008). A multidimensional approach to investigations of behaviour: revealing structure in animal communication signals Animal Behaviour DOI: 10.1016/j.anbehav.2008.05.026