Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus?☆
Correspondence information about the author Geoffrey Miller
Email the author Geoffrey Miller
Article InfoFig. 1
Effects of ovulatory cycle (Days 1–28) on average tip earnings per shift, for normally cycling women versus women using hormonal contraception (pill users); each data point represents a 3-day average of the indicated day, the previous day, and the following day.
Fig. 2
Effects of ovulatory cycle phase (menstrual phase, fertile estrous phase, or luteal phase) on tip earnings per shift, for normally cycling women versus women using hormonal contraception (pill users). Error bars represent 95% confidence intervals.
Abstract
To see whether estrus was really “lost” during human evolution (as researchers often claim), we examined ovulatory cycle effects on tip earnings by professional lap dancers working in gentlemen's clubs. Eighteen dancers recorded their menstrual periods, work shifts, and tip earnings for 60 days on a study web site. A mixed-model analysis of 296 work shifts (representing about 5300 lap dances) showed an interaction between cycle phase and hormonal contraception use. Normally cycling participants earned about US$335 per 5-h shift during estrus, US$260 per shift during the luteal phase, and US$185 per shift during menstruation. By contrast, participants using contraceptive pills showed no estrous earnings peak. These results constitute the first direct economic evidence for the existence and importance of estrus in contemporary human females, in a real-world work setting. These results have clear implications for human evolution, sexuality, and economics.
☆Brent D. Jordan's contribution to this project was supported by a McNair/ROP Scholars Program Fellowship.
