The type of implicit motive enactment is modulated by sex hormones in naturally cycling women.

Sex hormones have been reported to dynamically modulate the expression of implicit motives, a concept that has previously been thought to be relatively stable over time. This study investigates to what extent the need for affiliation, power, and achievement, as well as the form of enactment of these needs as measured with the Operant Motive Test (OMT), is affected by cycle-phase dependent sex hormone fluctuations. In addition to measuring the strength of motive expression, the OMT also captures different forms of motive enactment. In an intra-subject design with repeated measures, no evidence for cycle-phase related variation in overall motive scores was found. However, when different forms of motive enactment were considered, an effect of menstrual cycle was observed. The incentive-based inhibition of the power motive was significantly reduced at the time of ovulation, compared to the menstrual and to the mid-luteal phase, in naturally cycling women. In women with relatively stable hormone concentrations (due to using hormonal contraceptives), no significant changes in the form of motive enactment were evident. The results indicate a specific hormonal influence on motive-related cognitive processes that are related to inhibitive processes in behavior control.