Related Experiment Video
Updated: Jun 13, 2026

Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
Do bonobos say NO by shaking their head?
Christel Schneider1, Josep Call, Katja Liebal
1Evolutionary Psychology, Freie Universität Berlin, Berlin, Germany. schneide@eva.mpg.de
Abstract:
Head-shaking gestures are commonly used by African great apes to solicit activities such as play. Here, we report observations of head shaking in four bonobos apparently aimed at preventing the recipient from doing something. This may reflect a primitive precursor of the negatively connoted head-shaking behavior in humans. Further investigations are needed to clarify the preventive function of head shakes and their evolutionary role in the evolution of negation in humans.
Related Concept Videos
Facial Feedback Hypothesis
Nonconscious Mimicry
Non-Verbal Cues
Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
Obedience
Bending
In pure bending, the bending stress in a beam is calculated based on the bending moment and...

