"This is a fantastic example of how the response of cells changes due to a behavioral paradigm, " said theoretical neuroscientist Harel Shouval of the University of Texas Medical School at Houston, who was not involved in the study but has worked previously with the researchers.
Nor does empathy suggest a physiological "reason" for yawning (after all, we yawn when alone), though Dr. Provine thinks that it may be "a response to and facilitator of change in behavioral or physiological state, " maybe synchronizing a group of people about to embark on a behavioral transition.
"People are just beginning to think about modifying the immune inflammatory response to see if it has some sort of effect on behavioral symptoms, " says Dr. Hollander.