The validity of ‘;biorhythmic’ theory questioned

The study was of the relation between three categorical independent variables (cases in the critical, positive or regenerative phase of their 'biorhythmic' cycle) and two numerical independent variables, academic performance and factor scores on the psychoneurotic component of the University College London Study Questionnaire. The sample comprised 368 Open University students. A subset was used to study the relation between cases at the peaks and troughs of their cycles. If 'biorhythms' had any effect then it would be expected that the mean scores of the three subgroups would differ significantly. Results for 18 ANOVAs showed that none of the observed relations was greater than would be expected by chance.