However, this should result in an evolutionary arms race between the sexes, as men evolve ever-heightened sensitivity to signs of female fertility. Dr Miller thought lap-dancing clubs a good place to study this arms race, because male detection of female fertility cues would probably translate into an easily quantifiable signal, namely dollars earned. He therefore recruited some of the girls into his experiment, with a view to comparing the earnings of those on the Pill (whose fertility was thus suppressed) with those not on the Pill.
The results support the idea that if evolution has favoured concealed ovulation in women, it has also favoured ovulation-detection in men. The average earnings per shift of women who were ovulating was $335. During menstruation (when they were infertile) that dropped to $185—about what women on the Pill made throughout the month. The lessons are clear. A woman is sexier when she is most fertile. And if she wishes to earn a good living as a dancer, she should stay off the Pill.
Better know your lap dancer!