Biology: October 2007 Archives


October 7, 2007

ScienceNow reports on an interesting research project out of New Mexico:
The researchers used ads and flyers to sign up 18 lap dancers from local clubs. Each woman was asked to log on to a Web site and report her work hours, tips, and when she was menstruating. Lap dancers generally work 5-hour shifts with 18 or so 3-minute performances per shift. They average about $14 per "dance"--all of which is called a "tip" because it is illegal to pay for sex in New Mexico.

Over a 60-day period, the researchers collected data from 5300 lap dances. They divided the answers according to whether the dancers were in the menstrual phase, the high-fertility estrous phase, or the luteal phase. The result, as they report online this week in the journal Evolution and Human Behavior: Of the 11 women with normal menstrual cycles, those in the estrous phase pulled in about $70 an hour--compared with $50 for those in the luteal phase, and only $35 an hour for those who were menstruating. The other seven women were on birth control pills. They earned less across the board, and there was no peaking at the estrous phase.

The numbers suggest that men can tell when a woman is most fertile, although the message seems to be conveyed by "subtle behavioral signals" that evade conscious detection, the authors say. They add that the study couldn't identify whether it is scent or other physical changes that cue the men in, but they don't think it's anything obvious such as type of dance moves or "conversational content."

That's an interesting result. The paper doesn't seem to be online, but it would be interesting to know whether the variation is in the number of dances (18 over a 5 hour shift as opposed to 100 potential is a fairly low hit rate) or to the amount of tipping per performance. That might provide some indication of the nature of the effect.