Menstrual hut visits by Dogon women: a hormonal test distinguishes deceit from honest signaling

In humans the interests of males and females may conflict withrespect to the attribution of paternity. If a female has conceivedthrough adultery, or changes mates while she is in early pregnancy,she may protect her reproductive investment by misassigningpaternity. In Mali, West Africa, Dogon males attempt to preventfemale deception by mandating honest advertisement of menstruation(Strassmann, 1992). This advertisement takes place at a menstrualhut where women are on display to all the members of their husband'slineage. Knowledge of the timing of menstruation is pivotalbecause no other physiological event is as useful in paternityassessments. In this article I use hormonal data and a censusof menstrual hut visits to quantify female compliance with themenstrual taboos. The sample includes 93 women who providedurine samples twice weekly for 10 weeks. Analysis of urinarysteroid hormone metabolites (pregnanediol-3-glucuronide andestrone-3-glucuronide) demonstrates that the women went to themenstrual huts during 86% of all menses and, with the exceptionof one woman who may have been spotting, they never went tothe menstrual huts during pregnancy or amenorrhea. Thus themenstrual taboos of the Dogon were effective in eliciting honestsignals of female reproductive status (pregnant, amenorrheic,or cycling). This study is the first to use hormonal data totest the honesty of a human behavior in a nonlaboratory setting.It also establishes the feasibility of urinary enzyme immunoassaysas a tool for studying human reproduction in remote populations.Behav Ecol 7: 304-315 (1996)]