THE ASSESSMENT OF MENSTRUAL SYNCHRONY - COMMENT ON WELLER AND WELLER (1997)

A. Weller and L. Weller (1997) claimed to report ''the definitive stud y of menstrual synchrony'' (p. 148). To allow for cycle variability, t hey used the following criterion for synchrony: It occurred in 2 out o f 3 months. The underlying assumption of the state of menstrual synchr ony is that cycle length variability is minimal. The present article u ses a random selection of cycle lengths from a distribution described by R. F. Vollman (1977) to illustrate how variable cycle lengths cause a fluctuation from synchrony to a synchrony. A. Weller and L. Weller' s (1997) study is not, therefore, conclusive, and future studies of me nstrual synchrony should include an assessment of cycle variability as well as onset difference.