Biorhythmic Cycles and the Incidence of Industrial Accidents

The biorhythm theory of accident explanation that has been increasingly popularized in the business press was empirically examined. The data set consisted of municipal employees adjudged to be at fault in 150 work‐related vehicular accidents, and municipal employees involved in 210 on‐the‐job accidents resulting in workmen's compensation claims. Each accident case was analyzed to determine whether or not the accident occurred on a biorhythmically critical day. The results showed no systematic relationship between critical days and accident occurrences for these data groups. The data were also systematically evaluated for the existence of non‐biorhythmic cycles. The results of this analysis showed that no useful level of association existed for any cycle. It was concluded that, while other groups or events may exhibit measurable cyclical patterns, it seems likely that the relationships are more complex than a simple association such as that posited on the basis of biorhythm theory.