Cycling on the fast track: Ovulatory shifts in sexual motivation as a proximate mechanism for regulating life history strategies

In an ancestral world without modern contraception, how did women regulate their fertility? We argue that fertility may be regulated by context-dependent changes in sexual motivation that are specific to the high-fertility phase of the menstrual cycle. Accordingly, we predicted that ovulatory changes in sexual motivation would vary as a function of women's life history strategies, operationalized in terms of exposure to adverse childhood environments (high unpredictability, low SES, and low father quality). We tested this prediction in a sample of 1004 naturally cycling, pair-bonded women recruited using Amazon Mechanical Turk. Data show that women from adverse childhood backgrounds experienced higher in-pair sexual motivation and engaged in more in-pair sexual behavior at high fertility, compared to women from childhood backgrounds with low adversity. Women from low-adversity childhood backgrounds were more likely to exhibit ovulatory decreases in sexual motivation at early stages in their relationships. We found little evidence, however, that childhood environments interact with conception risk to predict women's extra-pair motivation and behavior. Results offer evidence that women may possess evolved psychological and behavioral mechanisms for regulating the timing of reproduction.