Also in this week's column:
- What colour is the most sexually attractive?
- Is heart rate correlated with birth order?
- Cross-cultural dispatches from the gender wars
Is Friday the 13th bad for your health?
Asked by Tanya Applegate of Ithaca, New York
Superstitions have existed since humans became humans. Research backing such superstitions is another matter entirely. In 1988, David Lester, a suicide specialist and professor of psychology at the Richard Stockton College in Pomona, New Jersey wrote a brief article in Psychological Reports arguing that in the US there is a statistically significant greater number of suicides and homicides on Friday the 13th.
In 1993, Dr T J Scanlon and three colleagues from the Department of Public Health at the Mid Downs Health Authority in West Sussex, presented evidence in the British Medical Journal that in the UK the number of hospital admissions due to transport accidents increases by as much as 52 per cent on Friday the 13th.
They write: "Friday [the] thirteenth is unlucky for some." They even suggest that "staying at home is recommended".
In 2002, in the Americal Journal of Psychiatry, Dr Simo Nayha from the Department of Public Health Science and General Practice at the University of Oulu in Finland, examined Finland's death statistics from 1971-1997.
According to Dr Nayha, this examination revealed that there was a statistically significant greater chance of dying in a traffic accident on Friday the 13th for women, but not for men. Dr Nayha went so far as to point out that "an estimated 38 per cent of traffic deaths involving women on this day were attributable to Friday the 13th itself".
Just how this comes about was less clear. Nayha's finding was disputed by Dr Donald Smith, a psychiatrist from Risskov, Denmark, in the same journal later that year. Nayha's finding was also challenged by Drs I Radun and H Summala of the Traffic Research Unit of the Department of Psychology at the University of Helsinki.
These two researchers were very familiar with the statistics Nayha had examined. Writing in the November 2004 BMC Public Health, after re-examining Nayha's figures and investigating figures from Fridays the 13th from 1989 to 2002, Radun and Summala conclude there were "no significant differences in any examined aspect of road injury accidents on Friday the 13th for either Finish men or women".
But that's not the "finish" of this research. Drs V V Kumar, N V Kumar, and G Isaacson, three specialists from the Department of Otolaryngology at Temple University School of Medicine in Philadelphia, investigated whether or not there is any truth to three beliefs often held by tonsillectomy specialists. The first is that more bleeding occurs in a tonsillectomy performed on a child with red hair. The second is that more bleeding occurs in a tonsillectomy performed during the day when there is a full moon at night. The third is that more bleeding occurs in a tonsillectomy performed on Friday the 13th.
Writing in the November 2004 Laryngoscope, the three doctors conclude that no evidence exists to support any of the three beliefs. Despite all of this, the superstition will no doubt continue that Friday the 13th is bad for your health.
Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to firstname.lastname@example.org