Not within spitting distance: Salivary immunoassays of estradiol have subpar validity for predicting cycle phase

Combined perceptual and chemical analyses show no compelling evidence for ovulatory cycle shifts in women's axillary odour

Although men's attraction to women's body odour has been suggested to vary over the ovulatory cycle, peaking around the fertile window, we still lack methodologically robust evidence corroborating this effect. Further, the chemical underpinnings of male preference for the odour of ovulating women remain unknown. Here, we combined perceptual and chemical analyses to investigate the axillary odour of naturally cycling women over 10 days, covering the gradual change in fertility across the ovulatory cycle with a focus on fertile days. The fertile state was confirmed by urinary ovulation tests as well as salivary oestradiol and progesterone levels. Men rated the scent of unfamiliar women, resembling a first encounter. We used multivariate analyses to relate variation in both odour ratings and chemical composition to female conception probability, temporal distance to ovulation and ovarian hormone levels. Our results provide no evidence that males prefer the odour of fertile women. Furthermore, the volatile analysis indicated no link between axillary odour composition and current fertility status. Together, our results showed no convincing support for a chemical fertility cue in women's axillary odour, questioning the presence of olfactory fertility information that is recognizable during first encounters in modern humans.

Salivary testosterone across the menstrual cycle

Testosterone production in women is thought to systematically shift across the menstrual cycle, peaking during the mid-cycle ovulatory window, and potentially influencing women's behavior. Testosterone is a molecular intermediary to the production of estradiol, which is necessary for ovulation to occur, but the amount of testosterone escape and exposure to the peripheral tissues is not fully understood. Salivary testosterone is a common biomarker in behavioral neuroendocrinological studies and is thought to reflect the bioactive portions in serum. In N = 339 women with confirmed ovulation via luteinizing hormone tests, salivary testosterone, assayed with LC-MS/MS, was sampled four times across the mid-cycle ovulatory window the luteal phase. Within-subject analysis revealed a significant but small pattern of a mid-cycle peak and a luteal decrease at the aggregate level. However, at the individual level, there was substantial variability in the direction and magnitude of the testosterone-cycle pattern. We discuss the relevant underlying physiology, background research, issues with assay methodolody, and considerations for researchers studying testosterone levels in women.

Hormonal and cycle phase predictors of within-women shifts in self-perceived attractiveness: Tests of alternative functional models

Prior research has produced mixed findings regarding whether women feel more attractive during the fertile phase of the menstrual cycle. Here, we analyzed cycle phase and hormonal predictors of women's self-perceived attractiveness (SPA) assessed within a daily diary study. Forty-three women indicated their SPA, sexual desire, and interest in their own partners or other potential mates each day across 1-2 menstrual cycles; saliva samples collected on corresponding days were assayed for estradiol, progesterone, and testosterone; and photos of the women taken at weekly intervals were rated for attractiveness. Contrary to some prior studies, we did not find a significant increase in SPA within the estimated fertile window (i.e., cycle days when conception is possible). However, within-cycle fluctuations in progesterone were significantly negatively associated with shifts in SPA, with a visible nadir in SPA in the mid-luteal phase. Women's sexual desire and SPA were positively associated, and the two variables fluctuated in very similar ways across the cycle. Third-party ratings of women's photos provided no evidence that women's SPA simply tracked actual changes in their visible attractiveness. Finally, for partnered women, changes in SPA correlated with shifts in attraction to own partners at least as strongly as it did with shifts in fantasy about extra-pair partners. Our findings provide preliminary evidence for the idea that SPA is a component of women's sexual motivation that may change in ways similar to other hormonally regulated shifts in motivational priorities. Additional large-scale studies are necessary to test replication of these preliminary findings.

Ovulatory cycle shifts in human motivational prioritisation of sex and food

Previous research on the endogenous effects of ovarian hormones on motivational states in women has focused on sexual motivation. The Motivational Priority Shifts Hypothesis has a broader scope. It predicts a shift from somatic to reproductive motivation when fertile. In a highly powered preregistered online diary study across 40 days, we tested whether 390 women report such an ovulatory shift in sexual and eating motivation and behaviour. We compared 209 naturally cycling women to 181 women taking hormonal contraceptives (HC) to rule out non-ovulatory changes across the cycle as confounders. We found robust ovulatory decreases in food intake and increases in general sexual desire, in-pair sexual desire and initiation of dyadic sexual behaviour. Extra-pair sexual desire increased mid-cycle, but the effect did not differ significantly in HC women, questioning an ovulatory effect. Descriptively, solitary sexual desire and behaviour, dyadic sexual behaviour, appetite, and satiety showed expected mid-cycle changes that were diminished in HC women, but these failed to reach our strict preregistered significance level. Our results provide insight into current theoretical debates about ovulatory cycle shifts while calling for future research to determine motivational mechanisms behind ovulatory changes in food intake and considering romantic partners' motivational states to explain the occurrence of dyadic sexual behaviour.

Influence of female sex hormones on proactive behavioral and physiological immune parameters

Women may be more susceptible to infections in the luteal phase, supposedly as a consequence of the hormone progesterone and its immunosuppressive action. While immunosuppression may be important for successful oocyte implantation and pregnancy, it makes women more vulnerable to pathogens. According to theory, to compensate for reduced immunocompetence, women in the luteal phase exhibit proactive behavioral responses, such as disgust and avoidance of disease-associated stimuli, to minimize contagion risk. However, previous studies yielded inconsistent results, and did not account for accompanying proactive immune responses, like the increase of secretory immunoglobin A (sIgA). Here, we assessed the proactive immune response and feelings of disgust associated with disease cues in the comparison of 61 woman with a natural menstrual cycle (31 in the follicular and 30 in the luteal phase) and 20 women taking hormonal contraception (HC). Women rated disease vulnerability and disgust propensity, watched a video displaying people with respiratory symptoms, which was evaluated for its disgust-evoking potential and contagiousness, and provided saliva samples for hormone and sIgA analysis. Women with HC reported a heightened vulnerability to disease compared to naturally cycling women, whereas both the feeling of disgust and the sIgA increase elicited by the disease video were similar across groups, regardless of progesterone. We found a u-shaped relationship between progesterone and baseline sIgA in naturally cycling women, with its nadir during ovulation. Overall, our data do not support a compensatory relationship between the proposed progesterone-induced immunosuppression and heightened disgust or a proactive sIgA response.

The search for the relationship between female hormonal status, alpha oscillations, and aperiodic features of resting state EEG

Fluctuations in sex steroid levels during the menstrual cycle and the use of hormonal contraceptives have been linked to changes in cognitive function and emotions in females. Such variations may be mediated by overall brain activity and excitability. We aimed to investigate the impact of female hormonal status on resting state EEG (rsEEG) parameters, including periodic (individual alpha frequency, alpha power) and aperiodic (1/f slope) features. rsEEG was recorded in healthy females (mean age 26.4 ± 4.6 years), who were naturally cycling in the early follicular (n = 33) or mid-luteal phases (n = 35), or who used either oral contraceptives (n = 35) or hormonal intrauterine devices (n = 28). Salivary concentrations of estradiol, progesterone, and testosterone were measured. Contrary to previous findings, this study did not reveal significant differences in rsEEG parameters between groups or significant relationships with hormonal levels. Age emerged as a covariate negatively related to the median 1/f slope. Based on these findings, we found no significant evidence to suggest that the periodic (alpha power and peak frequency) or aperiodic activity patterns in the brain during the resting state differ between the groups of females under investigation.

Extensive comparison of salivary collection, transportation, preparation, and storage methods: a systematic review

BACKGROUND

Human saliva as a bodily fluid-similar to blood-is utilized for diagnostic purposes. Unlike blood sampling, collecting saliva is non-invasive, inexpensive, and readily accessible. There are no previously published systematic reviews regarding different collection, transportation, preparation, and storage methods for human saliva.

DESIGN

This study has been prepared and organized according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 guidelines. This systematic review has been registered at PROSPERO (Registration ID: CRD42023415384). The study question according to the PICO format was as followed: Comparison of the performance (C) of different saliva sampling, handling, transportation, and storage techniques and methods (I) assessed for analyzing stimulated or unstimulated human saliva (P and O). An electronic search was executed in Scopus, Google Scholar, and PubMed.

RESULTS

Twenty-three descriptive human clinical studies published between 1995 and 2022 were included. Eight categories of salivary features and biomarkers were investigated (i.e., salivary flow rate, total saliva quantity, total protein, cortisol, testosterone, DNA quality and quantity, pH and buffering pH). Twenty-two saliva sampling methods/devices were utilized. Passive drooling, Salivette®, and spitting were the most utilized methods. Sampling times with optimum capabilities for cortisol, iodine, and oral cancer metabolites are suggested to be 7:30 AM to 9:00 AM, 10:30 AM to 11:00 AM, and 14:00 PM to 20:00 PM, respectively. There were 6 storage methods. Centrifuging samples and storing them at -70 °C to -80 °C was the most utilized storage method. For DNA quantity and quality, analyzing samples immediately after collection without centrifuging or storage, outperformed centrifuging samples and storing them at -70 °C to -80 °C. Non-coated Salivette® was the most successful method/device for analyzing salivary flow rate.

CONCLUSION

It is highly suggested that scientists take aid from the reported categorized outcomes, and design their study questions based on the current voids for each method/device.

Investigating cycle shifts in women's clothing style and grooming

In contrast to some non-human primate species, human females do not show overt cues to fertility. Previous research argued that women still show systematic changes in their appearance across their ovulatory cycle to enhance their mating success when fertile. We report five studies investigating whether women's clothing style and grooming behaviour change across the ovulatory cycle. All studies were large (with N = 157 in Study 1, N = 109 in Study 2, N = 257 in Studies 3-5), longitudinal studies with four testing sessions per participant. They involved salivary hormone samples and luteinizing hormone tests to validate conception risk estimates. Across all studies, our results suggest no compelling evidence for cycle shifts in clothing style and grooming. Rather, two studies suggest effects in the opposite direction as hypothesized, as women wore more skin-revealing clothes when non-fertile. One study suggests small effects of wearing necklaces more and eyeglasses less often when fertile. However, these effects were not robust across all studies. Our results are in line with other recent null replications and suggest that, if existent, cues to fertility might be even more subtle than previously assumed. We discuss the need for testing competing theories that explain the evolution of concealed ovulation.

Sex differences in mood, hormone and immune response to combatives training in West Point Cadets

Hand-to-hand combat training, known as combatives, instructs Soldiers in close-quarters combat techniques and how to cope with stress, understand controlled physical aggression, and develop self-confidence when engaged in such activities. Limited research in combat sports suggests men and women may respond to combatives stress differently. Given the increasing integration of women into close combat roles in the military, investigation of sex differences in the physiological and psychological response to combatives among military-trained personnel is warranted.

PURPOSE

This study was designed to identify sex differences in stress and gonadal hormones, mucosal immunity, and mood states in a military combatives training course.

METHODS

U.S. Military Academy Cadets (men = 144, women = 37) enrolled in a 2-month Combat Applications Course at West Point completed the Profile of Mood States and Competitive State Anxiety Inventory-2 and provided salivary samples at baseline prior to the course, and immediately prior to their midterm and final combat matches. Combat matches were gender- and weight-matched. Additional salivary samples were collected immediately following the first midterm and final matches. Salivary cortisol, testosterone, secretory immunoglobulin A (SIgA) and estradiol (women only) were measured via immunoassay. Men and women were compared over time with linear mixed effects models.

RESULTS

In both men and women, confusion, tension, anger, cognitive anxiety, somatic anxiety, and self-confidence increased throughout the course whereas friendliness and SIgA secretion rate decreased (all p < 0.05). Compared to women, men had a greater acute increase in cortisol from pre- to post-match (p = 0.043). Prior to the final match, women displayed higher ratings of tension (20.5 ± 9.3 vs. 16.0 ± 8.6) and cortisol (0.6 ± 0.3 vs. 0.4 ± 0.3 µg/dL) than men (all p < 0.05). After controlling for previous combative experience, ratings of tension did not differ by sex but remained elevated prior to midterm and final compared to baseline.

CONCLUSION

Combatives training elicited significant psychological and physiological stress and decreased mucosal immunity in both men and women. Women exhibited higher tension at the final match, likely due to lack of previous combative experience. Self-confidence increased from baseline suggesting that the skills learned may help Cadets prepare for combatives and other activities that require controlled aggression.

Does the interplay of emotion-related personality traits and reproductive hormones predict individual variation in emotion recognition?

Person-related variation has been identified in many socio-cognitive domains, and there is evidence for links between certain personality traits and individual emotion recognition. Some studies, utilizing the menstrual cycle as a hormonal model, attempted to demonstrate that hormonal fluctuations could predict variations in emotion recognition, but with merely inconsistent findings. Remarkably, the interplay between hormone fluctuations and other person-related factors that could potentially influence emotion recognition remains understudied. In the current study, we examined if the interactions of emotion-related personality traits, namely openness, extraversion, and neuroticism, and the ovulatory cycle predict individual variation in facial emotion recognition in healthy naturally cycling women. We collected salivary ovarian hormones measures from N = 129 (n = 72 validated via LH test) women across their late follicular and mid-luteal phases of the ovulatory cycle. The results revealed a negative association between neuroticism scores and emotion recognition when progesterone levels (within-subject) were elevated. However, the results did not indicate a significant moderating influence of neuroticism, openness, and extraversion on emotion recognition across phases (late follicular vs. mid-luteal) of the menstrual cycle. Additionally, there was no significant interaction between openness or extraversion and ovarian hormone levels in predicting facial emotion recognition. The current study suggests future lines of research to compare these findings in a clinical setting, as both neuroticism and ovarian hormone dysregulation are associated with some psychiatric disorders such as premenstrual dysphoric disorder (PMDD).

Morphologic alterations of the fear circuitry: the role of sex hormones and oral contraceptives

Background

Endogenous sex hormones and oral contraceptives (OCs) have been shown to influence key regions implicated in fear processing. While OC use has been found to impact brain morphology, methodological challenges remain to be addressed, such as avoiding selection bias between OC users and non-users, as well as examining potential lasting effects of OC intake.

Objective

We investigated the current and lasting effects of OC use, as well as the interplay between the current hormonal milieu and history of hormonal contraception use on structural correlates of the fear circuitry. We also examined the role of endogenous and exogenous sex hormones within this network.

Methods

We recruited healthy adults aged 23-35 who identified as women currently using (n = 62) or having used (n = 37) solely combined OCs, women who never used any hormonal contraceptives (n = 40), or men (n = 41). Salivary endogenous sex hormones and current users' salivary ethinyl estradiol (EE) were assessed using liquid chromatography - tandem mass spectrometry. Using structural magnetic resonance imaging, we extracted surface-based gray matter volumes (GMVs) and cortical thickness (CT) for regions of interest of the fear circuitry. Exploratory whole-brain analyses were conducted with surface-based and voxel-based morphometry methods.

Results

Compared to men, all three groups of women exhibited a larger GMV of the dorsal anterior cingulate cortex, while only current users showed a thinner ventromedial prefrontal cortex. Irrespective of the menstrual cycle phase, never users exhibited a thicker right anterior insular cortex than past users. While associations with endogenous sex hormones remain unclear, we showed that EE dosage in current users had a greater influence on brain anatomy compared to salivary EE levels and progestin androgenicity, with lower doses being associated with smaller cortical GMVs.

Discussion

Our results highlight a sex difference for the dorsal anterior cingulate cortex GMV (a fear-promoting region), as well as a reduced CT of the ventromedial prefrontal cortex (a fear-inhibiting region) specific to current OC use. Precisely, this finding was driven by lower EE doses. These findings may represent structural vulnerabilities to anxiety and stress-related disorders. We showed little evidence of durable anatomical effects, suggesting that OC intake can (reversibly) affect fear-related brain morphology.

Women in their mid-follicular phase outcompete hormonal contraceptive users, an effect partially explained by relatively greater progesterone and cortisol reactivity to competition

Early evidence suggests that hormonal contraceptive (HC) use alters psychological functioning and competitive behavior. Yet, there is limited data on endocrine models for explaining how HC use affects these outcomes. In this pre-registered and open-data study, we test if HC users and naturally cycling (NC) females in their low (mid-follicular) and high (mid-luteal) progesterone phase differ in competitive persistence and whether progesterone and cortisol reactivity mediate of this effect. HC users (N = 73) in the active hormone-exposure phase and NC participants in the mid-follicular (N = 69) or mid-luteal (N = 72) phase completed two behavioral measures of competitive persistence, holding up a weight for time followed by attempting to solve an unsolvable anagram. Participants also completed measures of handgrip strength and self-reported competitiveness as well as gave saliva samples before and after the tasks for hormone assay. Results showed that NC-follicular group had greater competitive persistence in the weight-holding task compared to both NC-luteal (d = 0.38) and HC use (d = 0.43) groups independent of physical strength and self-reported competitiveness covariates. Although anagram task performance showed similar trends for group differences, analyses for this task were inconclusive. Baseline progesterone did not mediate the effect of cycle phase group on competitive persistence. HC users showed relatively blunted cortisol and progesterone reactivity, and this effect partially mediated the difference in competitive persistence between HC users and the NC-follicular group. In sum, results suggest that HC use could downregulate competitive behavior at least partly by dampening cortisol-progesterone reactivity. These findings offer a new endocrine model for understanding HC use and cycle phase effects on motivational and energetic outcomes required for optimal performance in competitive contexts.

An empirical comparison of several commercial enzyme immunoassays for the non-invasive assessment of adrenocortical and gonadal function in mountain gorillas

Wildlife researchers seeking to non-invasively examine endocrine function in their study species are presented with a dense and technical 'garden of forking paths' to navigate between collecting a biological sample and obtaining a final measurement. In particular, the choice of which enzyme immunoassay (EIA) to use with collected fecal samples, out of the many options offered by different manufacturers and research laboratories, may be one of the most consequential for final results. However, guidance for making this decision is still emerging. With this gap in mind, we performed a head-to-head comparison of results obtained from four different EIAs for fecal glucocorticoid metabolites (FGCMs), and three different EIAs for fecal androgen metabolites (FAMs), applied to the same set of fecal samples collected from the mountain gorillas (Gorilla beringei beringei) monitored by the Dian Fossey Gorilla Fund in Volcanoes National Park, Rwanda. We provide a) an analytical validation of the different EIAs via tests of parallelism and linearity; b) an estimate of inter-assay correlation between EIA kits designed for the same metabolites; and c) a test of the kits' ecological validity, in which we examine how well each captures endocrine changes following events that theory predicts should result in elevated FGCM and/or FAM concentrations. Our results show that kits differ to some degree in their performance; at the same time, nearly all assays exhibited at least moderate evidence of validity and covariance with others for the same analyte. Our findings, which differ somewhat from similar comparisons performed in other species, demonstrate the need to directly assess assay performance in a species- and context-specific manner as part of efforts to develop the burgeoning discipline of wildlife endocrinology.

Revisiting the Relation Between Steroid Hormones and Unethicality in an Exploratory, Longitudinal Study With Female Participants

Research on the relation between hormones and unethical behaviors and tendencies has provided mixed results, hindering the understanding of the potential biological regulation of unethical behaviors and tendencies. We conducted an exploratory, longitudinal study (N = 257 women) allowing to estimate relations between, on the one hand, steroid hormones (testosterone, cortisol, estradiol, and progesterone) and conception probability and, on the other hand, a broad variety of measures related to unethicality (self-reported personality variables, cheating in committed relationships, self-serving economic dishonesty in a behavioral task, namely, the mind game). Contrary to theoretical assumptions of and results from some previous studies, we find no consistent relation between hormones and unethical behavior or tendencies in the majority of analyses. Yet, some small, exploratory associations emerged that call for (preregistered) replications, before more firm conclusions can be made.

Determining menstrual cycle phase: An empirical examination of methodologies and recommendations for improvement in behavioral and brain sciences

The recent decade has brought an exciting proliferation of behavioral, psychological and neuroscientific research involving the menstrual cycle. However, the reliability and validity of many popular methodologies for determining menstrual cycle phase lack empirical examination. These under-investigated methods include: (1) predicting menstrual cycle phase using self-report information only (e.g., "count" methods), (2) utilizing ovarian hormone ranges to determine menstrual cycle phase, and (3) using ovarian hormone changes from limited measurements (e.g., two time points) to determine menstrual cycle phase. In the current study, we examine the accuracy of these methods for menstrual cycle phase determination using 35-day within-person assessments of circulating ovarian hormones from 96 females across the menstrual cycle. Findings indicate that all three common methods are error-prone, resulting in phases being incorrectly determined for many participants, with Cohen's kappa estimates ranging from -0.13 to 0.53 indicating disagreement to only moderate agreement depending on the comparison. Such methodological challenges are surmountable through careful study design, more frequent hormone assays (when possible), and utilization of sophisticated statistical methods. With increased methodological rigor in behavioral, psychological and neuroscientific research, the field will be poised to detect biobehavioral correlates of ovarian hormone fluctuations for the betterment of the mental health and wellbeing of millions of females.

Emotion recognition and mood along the menstrual cycle

Previous studies have demonstrated menstrual cycle dependent changes in the recognition of facial emotional expressions, specifically the expression of fear, anger, sadness or disgust. While some studies demonstrate an improvement of emotion recognition performance during the peri-ovulatory phase, when estradiol levels peak, other studies demonstrate a deterioration of emotion recognition performance during the mid-luteal phase, when progesterone levels peak. It has been hypothesized, that these changes in emotion recognition performance mirror mood changes along the menstrual cycle. In the present study, we investigate, whether changes in emotion recognition performance along the menstrual cycle are mediated by mood changes along the menstrual cycle. In a combined cross-sectional and longitudinal study design, two large samples of women completed an emotion recognition task, as well as several mood questionnaires during their menses, peri-ovulatory or mid-luteal cycle phase. 65 women completed the task thrice, once during each cycle phase, order counterbalanced. In order to control for potential learning effects, a sample of 153 women completed the task only once in one of the three cycle phases. In both samples, results demonstrated no significant changes in emotion recognition performance along the menstrual cycle, irrespective of the performance measure investigated (accuracy, reaction time, frequency of emotion classifications) and irrespective of the emotion displayed. Bayesian statistics provided very strong evidence for the null hypothesis, that emotion recognition does not change along the menstrual cycle. There was also no moderation of emotion recognition changes along the menstrual cycle by mood changes along the menstrual cycle. Mood changes along the menstrual cycle followed the expected pattern with highest positive affect and least premenstrual symptoms around ovulation and lowest positive affect, but strongest premenstrual symptoms during menses. Interestingly, premenstrual symptoms were negatively related to estradiol, suggesting a protective effect of estrogen during the luteal cycle phase against mood worsening during the premenstrual phase.

A Mid-Cycle Rise in Positive and Drop in Negative Moods among Healthy Young Women: A Pilot Study

Clinically oriented studies of mood as a function of the menstrual cycle mainly address the negative moods in the premenstrual phase of the cycle. However, a periovulatory increase in positive emotions and motivations related to reproduction has also been noted. Thus, it has been suggested that the drop in mood during the luteal phase of the menstrual cycle might be a byproduct of elevated positive moods occurring mid-cycle. The aim of this prospective study was to compare both the positive and negative dimensions of mood across the menstrual cycle. A group of 60 healthy, normally cycling women assessed their mood throughout three phases of their menstrual cycles: the early follicular (low estradiol and progesterone), the late follicular (fertile phase; high estradiol, low progesterone) and the mid-luteal phase (high levels of both estradiol and progesterone). Repeated MANOVA evaluations showed a significant increase in positive (friendly, cheerful, focused, active) and a significant decrease in negative (anxious, depressed, fatigued, hostile) dimensions of mood mid-cycle, i.e., during the late follicular phase (η2 = 0.072−0.174, p < 0.05). Contrary to the widespread belief that negative moods are characteristic of the luteal phase (preceding the onset of the next cycle), the post hoc Bonferroni tests showed that none of the mood dimensions differed between the mid-luteal and early follicular phases of the cycle. The results held when controlling for relationship status and order of testing. This pattern of fluctuations is in accordance with the ovulatory-shift hypothesis, i.e., the notion that the emotions of attraction rise during a short window during which the conception is likely.

Is Pathogen Disgust Increased on Days of the Menstrual Cycle when Progesterone is High? Evidence from a Between-Subjects Study Using Estimated Progesterone Levels

Objective

The Compensatory Prophylaxis Hypothesis proposes that women will show increased pathogen disgust at points in the menstrual cycle when progesterone is high, compensating for the immunosuppressive effects of progesterone. However, evidence for the Compensatory Prophylaxis Hypothesis from studies that used longitudinal designs to investigate whether pathogen disgust tracks changes in progesterone is mixed. It was recently proposed that longitudinal designs may be poorly suited to testing the Compensatory Prophylaxis Hypothesis because carry-over effects when women are tested repeatedly in within-subject designs might obscure the effects of progesterone and pathogen disgust. Consequently, we used a between-subjects design to test for a positive relationship between scores on the pathogen disgust subscale of the Three Domain Disgust Scale and progesterone levels imputed from menstrual cycle data using actuarial tables.

Methods

We employed a between-subject design on N = 1346 women using the Three Domains of Disgust Scale (TDDS).

Results

We found no evidence for a positive effect of progesterone on pathogen disgust, suggesting that null results for the hypothesized relationship between progesterone and pathogen disgust are not limited to studies using designs that may be subject to carry-over effects caused by repeated testing.

Conclusion

Our results add to a growing body of research that does not support the Compensatory Prophylaxis Hypothesis.