Abstract
This is a study of some rhythmic components of human behaviour. A sample of 109 (including 40 psychiatric patients) completed a long term daily assessment of psychological and other measures, namely pulse rate, body temperature, body weight, performance test (digit symbol/word cancellation) and subjective ratings of mood. The raw data obtained in this way was then subjected to rigorous statistical analysis by Fourier transformation. The extracted power spectrum was further subjected to Fisher's F-ratio. The resulting data indicated the presence of significant rhythms within a restricted bandwidth, having periods from 23 to 31 days. Different variables were found to be associated with slightly different frequencies, and the interindividual differences were, marked. Thus, although the interindividual consistency was acceptable, prediction of an individual's position on any cycle could not be made without first assessing the period for that individual. There was no marked sex or age difference within the groups. Psychiatric patients have shown significant differences in frequency of rhythms between the measures of performance, body weight and sleep rhythms. This study has established the existence of some long term rhythms in human behaviour and experience, but because of the duration of measurement, was not able to establish to what extent changes in future rhythmic behaviour or experience could be predicted. The limitations in the present study are discussed and suggestions for further research provided.