Any sufferer knows: Carsickness runs in the family.
But is it genetic, or just the power of persuasion? When Mom turns green, is that what makes Sis queasy?
Penn State psychologist Robert M. Stern and gastroenterologist Kenneth L. Koch have studied motion sickness for many years, sitting volunteers, motionless, inside a horizon-shattering rotating drum (see R/PS September 1988). The insights gained from that nausea-inducing set-up have helped people as diverse as astronauts and mothers-to-be with morning sickness.
But over the years, Stern and Koch noticed an odd pattern: Their Chinese volunteers succumbed more acutely than those of European or African heritage.
With graduate students Eric R. Muth and Sebastian Uijtdehaage, Stern and Koch designed an experiment to rule out the effects of environmental differences: They recruited American-raised volunteers with Asian parents.
As they reported at meetings in Hungary and Germany in October 1993, the Asian-Americans "were hyper-susceptible to motion sickness compared to a primarily European-American control group." They reported far more symptoms. Many asked for the test—that whirling drum—to be stopped early.
"Now we are reasonably certain that inheritance plays a role in motion sickness," Stern said.
"This link to ancestry," Koch added, "probably indicates why some sick people may be more difficult to treat than others. They get sicker faster and need higher doses of medication."
"Each new finding," concluded Stern, "is a step toward pinpointing the causes and ways to prevent all types of nausea, including nausea induced by chemotherapy."
Robert M. Stern, Ph.D., is distinguished professor of psychology in the College of the Liberal Arts, 512 Moore Building, University Park, PA 16802; 814-865-1712. Kenneth L. Koch, M.D., is professor of medicine in the College of Medicine, Milton S. Hershey Medical Center, 500 University Drive, Box 850, Hershey, PA 17033; 717-531-8390. Sebastian H.J. Uijtdehaage received his Ph.D. in psychology from Penn State and is now a research associate at U.C.L.A. Eric R. Muth is a graduate students in psychology at Penn State. This research was presented to the Society for Psychophysiological Research and the German Space Agency and published in Electrogastrography: Principles and Applications (Raven Press, May 1994) Reported by Scott Turner.