May 05, 2006
Ripples of yawn:
Seed Magazine has a short but thought-provoking article on the yawn and the mysterious way they are 'transmitted' around a social group.
Scientists maintain that yawning has both social and physiological functions, and may even be useful clinically: Abnormal yawning can be symptomatic of pathology, such as tumors, hemorrhage or drug withdrawal. Researchers know that a system of several neurotransmitters and neuropeptides control yawning, but little is known about the exact mechanism underlying the action.
Until recently, it was thought that only humans and great apes were able to "catch" yawns. While humans yawn in the womb, they don't fall prey to contagious yawning until about two years of age, which suggests a recent evolutionary origin.
The article also tackles the myth that yawns are brought on by lack of oxygen.
Link to 'The Incredible, Communicable Yawn' from Seed Magazine.
