Psychosocial and biological influences on menstruation: synchrony, cycle length, and regularity

Multiple influences on menstrual synchrony: Kibbutz roommates, their best friends, and their mothers

“…The degree of friendship among roommates was also not related to synchrony, as also noted by Jarett (1984) and Matteo (1987), while the subjects were apparently synchronized with their best friends. Very possibly, the large amount of time that roommates spend together causes such an intensity of pheromonal exchange andor provides a substantial "common environment" that it overrides any additional influences of friendship.…”

“…It seems, therefore, that the inclusion of women with irregular cycles both in this research and in the other studies may not have weakened the findings. Jarett (1984) suggested that the failure t o find menstrual synchrony may have been due to the prevalence of menstrual irregularity in her sample. Our findings suggest that this may not be so.…”

Environmental influences cause menstrual synchrony, not pheromones

“…Pheromonal influences have been suggested as a possible cause of menstrual synchrony based on animal studies (Karlson and Luscher, 1959), but there have been conflicting or equivocal findings in previous human studies (McClintock, 1971;Quadagno et al, 1981;Graham and McGrew, 1980;Russell et al, 1980;Jarett, 1984). In the present study, if pheromonal effects were important, roommates and coresidents should have been significantly synchronized and women who did not live together should not have synchronized.…”

The Role of the Vomeronasal Organ in Behavioral Control of Reproduction

“…What is the likelihood that there are one or more functional human pheromones," just as there seem to be functional prosimian primate pheromones?" More than 20 years ago Wil~on'~ noted that human "primer pheromones might be difficult to detect since they can affect the endocrine system without producing overt specific behavioral Experimental Findings (1978-198419801980, 1981198019811983198319841984 Mediates male urine-induced reflex ovulation in anovulatory rats.' Mediates suppression of estrus in grouped mice.…”