Time series methodology in the study of sexual hormonal and behavioral cycles

This paper addresses problems in the study of sexual behavior that require the detection of cyclicity in one set of data over time and synchronicity in two sets of data over time. Time-series analysis is discussed, in particular, the use of the spectral density function and coherence. The proposed methods are then applied to the study of hormonal levels in young couples as a function of the wives' menstrual cycles.