Examining Changes in Long-Term Couples’ Relationship Satisfaction,Mate Guarding Behaviors,and Jealousy Across the Menstrual Cycle

Abstract

Using the Ovulatory Shift Hypothesis framework, this study investigated if hormonal fluctuations affected mate guarding behaviors, jealousy, and relationship satisfaction in long-term couples. Committed, heterosexual couples (N = 98, n = 49 pairs) completed daily surveys tracking relationship dynamics for one menstrual cycle (e.g., 28 days; all naturally cycling). Analysis showed partners’ relationship satisfaction, jealousy, and mate guarding behaviors were positively correlated. Results also showed men’s relationship satisfaction was correlated with their partner’s mate guarding behaviors when she menstruated. Dependent t-tests showed mate guarding behaviors increased during menses compared to the fertile phase. Finally, regression analysis, showed that jealousy and mate guarding behaviors predicted relationships when the female partner menstruated. When the female partner was in her fertile phase, only mate guarding behaviors positively predicted relationship satisfaction. Findings demonstrate the ovulatory shift hypothesis may not be applicable in established couples who may be making the conscious decision to remain committed to their romantic partner. In couples where mate guarding and jealousy are low; counselors should reframe these behaviors as a demonstration of relationship investment.

Keywords

couples hormones fertility jealousy mate guarding relationship satisfaction ovulation menstruation

The menstrual cycle is driven by hormonal fluctuations that may alter cognitive and affective processing (Sacher et al., 2013). For example, luteinizing hormone may increase sexual desire, follicle stimulating hormone may improve mood, estrogen may enhance cognitive processing, and progesterone may produce a calming effect (Brizendine, 2006). Research is only beginning to understand the subtle nuances explaining how hormones may be implicated in mental health functioning (e.g., estrogen and progesterone changes are linked to depression and anxiety; Kundakovic & Rocks, 2022). Distinct areas in the brain (i.e., the amygdala, hypothalamic–pituitary–adrenal axis) may be particularly sensitive to estrogen and progesterone fluctuations, perhaps explaining changes in mood associated with the menstrual cycle (Albert & Newhouse, 2019). While it may appear only menstruating people are the subject to monthly mood variations, research suggests nonmenstruating people (e.g., men) may also be vulnerable (Hirschenhauser et al., 2002). While menstruation is not exclusive to those identifying as women and nonmenstruating persons is not exclusive to men, throughout this article, we will use the gendered language as defined in the referenced articles and participants reported gender. Thus, while the language used may imply exclusivity to men and women, statements should be interpreted as specific to the population self-reported gender.

Beyond the influence on individual mood changes, relationship satisfaction may vary across the menstrual cycle as a function of sexual desire for one's romantic partner (Larson et al., 2012). For example, women's relationship satisfaction may increase if they view their mate as highly sexually desirable, yet it may decrease if they view their mate as low in sexual desirability. Furthermore, factors like jealousy and mate guarding/retention that vary alongside fertility shifts may impact relationship satisfaction (Buunk & van Brummen-Girigori, 2016). Increased jealousy during peak fertility windows observed across men and women, is potentially a response to females’ increased likelihood of extra-partner copulation during high fertility (Baker & Bellis, 1995). These changes in couple dynamics may foster jealousy in men and prompt them to increase their mate guarding/retention behaviors, leading to diminished, overall, relationship satisfaction (Fugère et al., 2015). The amalgam of relationship satisfaction, jealousy, mate guarding/retention, and the menstrual cycle are interrelated. Research is needed to concurrently understand the intersectionality of these variables with established couples.

Ovulatory Shift Hypothesis

The Ovulatory Shift Hypothesis (OSH; Gangestad et al., 2005; Gangestad & Thornhill, 1998) proposes preferences for specific male characteristics and sexual motivation fluctuate across the menstruation cycle (Gildersleeve et al., 2014). This framework assumes people who menstruate (PWM) are more attracted to interpersonal characteristics that resemble high genetic quality during high fertility windows (Gangestad & Thornhill, 1998; Gildersleeve et al., 2014; Larson et al., 2012). The purpose of this attraction, from an evolutionary perspective, ensures reproductive success and secure genetic benefits to their offspring in PWM (Gildersleeve et al., 2014). The OSH principles are theorized to be specific to evaluations of short-term partners, and notably weaker when evaluating long-term partners (Gildersleeve et al., 2014). In short, according to the OSH, attraction to different traits vary and shift across the ovulatory cycle (Gildersleeve et al., 2014; Larson et al., 2012).

While many mammal species exhibit overt physical and behavioral changes prior to ovulation (e.g., changes in physical appearance and pheromone release) to increase success of attracting a mate, human ovulation is comparatively concealed (Fišar et al., 2023). Nevertheless, empirical evidence, including the seminal work by Gangestad and Thornhill (1998) involving scent evidence for symmetrical features, supports the existence of increased sexual attraction to specific genetic markers during peak fertility. Conversely, women using a contraceptive pill and women on low-fertility days did not show a preference for symmetrical or asymmetrical scents. Support for the OSH was substantiated via a meta-analytic review (Gildersleeve et al., 2014) noting robust shifts mid-cycle for genetic quality preferences and women's differences in their evaluation of short- and long-term partners (Larson et al., 2012; Pillsworth & Haselton, 2006).

A body of research continues to support OSH. Both Gangestad et al. (2005) and Larson et al. (2012) demonstrated fertile women reported increased attraction to extra-dyadic partners, suggesting the hypothesis applied primarily to attraction to short-term mate preferences. Pillsworth and Haselton (2006) refined this claim when observing women may report attraction to an extra-dyadic partner during ovulation when they perceive their long-term partner as less attractive. Research also demonstrated male partners became more vigilant of their fertile female partners (Gangestad et al., 2005) suggesting shifts in extra-dyadic attraction may be driven by bidirectional behavioral adaptations.

Jealousy and Mate Guarding by Fertility Status

Jealousy is an emotional response that may be experienced in the context of romantic partnering in response to romantic relationship threats. Women in romantic relationships may report more jealousy during ovulation and while using hormonal contraceptives (Cobey et al., 2012); although this may be dose dependent (Cobey et al., 2011). Men may reciprocate this emotion and be more prone to jealousy and more possessive of their romantic partners when she is ovulating (Haselton & Gangestad, 2006). For women, their reported jealousy may increase when the relationship threat is in her peak fertility (Hurst et al., 2017).

Mate guarding may be seen as the behavioral manifestation of jealousy. Mate guarding is defined as participating in strategies designed to preserve access to a mate, prevent encroachment of intrasexual rivals, and prevent a mate from leaving the relationship (Arnocky et al., 2014; Buss, 1988, 2002; Husárová, 2005). Mate guarding behaviors differ by gender (e.g., men display resources to attract partners and women focus on appearance to attract partners; Buss, 1988, 2002). Mate guarding behaviors directed at a romantic partner may be compartmentalized according to domains focused on directly guarding a romantic partner, behaviorally manipulating a partner or extra-dyadic threat, and displays of affection to support mate retention (Buss, 1988). Mate guarding behaviors appear to be driven by emotional response. The increase of vigilance experienced by male partners observed by Gangestad et al. (2005) correlates with an increase in mate guarding behaviors (Arnocky et al., 2014; Haselton & Gangestad, 2006; Husárová, 2005). Other factors contributing to an increase of mate guarding behaviors include perceived mate scarcity (Arnocky et al., 2014), attraction (Haselton & Gangestad, 2006), jealousy (Arnocky et al., 2014; Buss, 1988, 2002; Haselton & Gangestad, 2006), fertility status (Husárová, 2005), and perceived threats by intrasexual rivals (Arnocky et al., 2014; Husárová, 2005). How women respond to their partners’ mate guarding behaviors may be dependent on fertility status (i.e., women may be particularly resistant to their male partner's mate guarding behaviors during their peak fertility days; Gangestad et al., 2016).

Haselton and Gangestad (2006) reviewed daily reports of sexual interests from 38 normally cycling undergraduate women across 35 days to identify intensity of mate guarding and levels of jealousy by primary partners. They found that women who were partnered with less sexually attractive men experienced higher levels of male mate guarding during the high fertility phase of the menstrual cycle (Haselton & Gangestad, 2006). These same women reported more extra-dyadic attraction toward men when fertile, which coincided with higher levels of jealousy and more possessive behaviors from their male partners (Haselton & Gangestad, 2006). These findings are consistent with previous findings noting men's feelings of jealousy and mate guarding behaviors changed based on perceived relationship threats (Buss, 1988, 2002; Husárová, 2005).

Despite Husarova's work identifying fertility status as a predictor of jealousy and mate guarding behaviors, empirical investigations remain limited. Arnocky et al. (2014) observed both jealousy and aggression fluctuate in response to perceived mate availability. Specifically, individuals primed with a mate scarcity article exhibited more jealousy and higher intrasexual competition and indirect aggression. Interestingly, women were more likely to be aggressive than men. Exclusive to women, in a meta-analysis reporting findings across three studies using vignettes or personal reflections to inform jealousy and mate guarding responses, women were more likely to feel threatened when a competitive extra-dyadic female was ovulating (Hurst et al., 2017), aligning with earlier findings on jealousy, possessiveness, and mate guarding with intrasexual rivals (Buss, 1988; Haselton & Gangestad, 2006; Husárová, 2005).

Relationship satisfaction may serve as a moderating factor critical in the association with jealousy and mate guarding. Righetti et al. (2020), in their 15-day daily diary study with couples, noted that rises in estrogen,correlated with fertility, were linked to self-reported lower relationship satisfaction across genders and partner reported perceptions of their partner having lower relationship satisfaction. Righetti and colleagues did not observe changes in jealousy by hormone status. Schleifenbaum et al. (2022) reported consistent findings with couples using a 30-day daily diary method, noting men reported no significant changes in jealousy and mate guarding behaviors across their female partner's menstrual cycle. They further added that women also did not find men's behaviors changed.

The Current Study

The OSH was originally developed within the context of noncommitted couples to explain changes in desire and sexual pursuit; consequently, these shifts may manifest differently in long-term relationships. Current research often relies on undergraduate samples or unpartnered individuals, leaving a gap in understanding if hormonal fluctuations affect established couples and their behavioral dynamics. The present study examined the influences of hormonal variations on romantic relationships across the menstrual cycle. We predicted (1) Romantic partners will display more mate guarding/retention behaviors and jealousy during the female partner's fertile phase compared to the menstrual phase; (2) Relationship satisfaction will increase during the fertile phase and decrease during the menstrual phase; (3) Relationship satisfaction will be negatively related to jealousy and mate guarding behaviors during both the fertile and menstrual phase.

Methods

Participants

A total of 49 couples (98 subjects, 49 men/women) participated in this study. The majority of participants identified as heterosexual (n = 94) with four individuals identifying as pan or bisexual. Participants ranged in age from 20 to 51 (M = 30.79, SD = 6.66). The sample was well educated; 11 participants earned a high school diploma or GED, two participants completed trade school, eight participants earned an associate's degree, 50 earned a Bachelor's degree, 25 earned a master's degree, and 12 participants earned a doctorate or professional degree. The majority of the sample was white (n = 53), followed by Asian (n = 20), African American (n = 9), Multiracial (n = 7), Latino (n = 6), and American Indian (n = 3). The couples on average had been with their romantic partner for 7.89 years (range 1–23 years, SD = 5.74). Income ranged from $2 to $300,000 (M=$79, l72; SD=$56,694).

Procedures

Potential participants learned about the study through advertisements posted around the community, on the university campus, on the university listserv, on craigslist, and on social media. From the advertisements, potential participants were directed to an online screener to determine eligibility to participate in the study. If they meet all study criteria, the final page of the screening survey included contact information for the primary investigator (PI). Interested individuals contacted the PI. The PI vetted all potential participants and reviewed the study including describing the nature of the study, the participant's role in the study, how to participate in the study, and that couples would receive a gift card for their participation.

Participant Criteria

To participate in the study both romantic partners agreed to participate, one member of the romantic couple needed to have regular menstrual cycles (i.e., every 24–35 days), the couple needed to have been in a committed relationship with each other for at least 1 year, both partners needed to be aged 21 or older, the couple needed to physically sleep in the same bed at least once a week, and on average, the couples needed to see each other every day. Participants were excluded from the study if the menstruating partner was using hormonal birth control (e.g., the pill, the patch, and a vaginal ring) or other hormones (e.g., hormone replacement therapy and hormones for egg retrieval), a partner was pregnant or trying to become pregnant, if a partner was nursing, if either partner was using medication for a psychiatric condition, if either partner had a psychiatric diagnosis, if either partner used nicotine products, and if either partner was using any illegal or mind altering substances.

Study Details

After participants agreed to participate in the study, participants were given a participant ID to use every time they logged into the survey. Participants provided an email address for a research team member to contact them to send them links to a daily survey. The participants completed daily surveys across one menstrual cycle. They started the survey on day 1 of their or their partner's menstrual cycle and ended the surveys on the final day of the menstrual cycle (i.e., the day before they started their next period). Menstruation was indicated by the first day of blood flow and was calculated as 5 days. Peak fertility days were also tracked on a 5-day window as described in Larson et al. (2012). Fertility was determined by using an application to track ovulation and confirmed by the reported first day of the next menstrual cycle. If participants did not complete their daily survey, a member of the research team emailed the participant to remind them to complete their survey. If participants missed 3 or more days, they were not asked to make up surveys and to begin surveys on the current day. Surveys were supposed to be completed in the evenings and participants were told to reflect on their entire day. Surveys took 5 to 15 min to complete. After completing the study, couples were thanked with gift cards. To receive the gift certificate, both members of the couple needed to complete 90% of surveys across the menstrual cycle.

Instruments

Relationship Satisfaction

The Relationship Assessment Scale (RAS; Hendrick et al., 1988) measured relationship satisfaction. This reported reliable measure (α = .86) demonstrates convergent validity with the Dyadic Adjustment Scale. Scores for this instrument range from 7 to 35. The sample mean when the female partner menstruated was 22.01 (SD = 3.24). The sample mean when the female partner was fertile was 22.28 (SD = 2.91).

Jealousy

The emotional subscale of the Multidimensional Jealousy Scale—Short-form (Elphinston et al., 2011) measured jealousy. Reliability for the subscale is acceptable (α = .81 l) and there is evidence of convergent validity with the original version of the Multidimensional Jealousy Scale (Pfeiffer & Wong, 1989). Scores on this instrument range from 15 to 105. The menses mean for the sample was 42.11 (SD = 4.52). The fertility mean was 42.52 (SD = 4.87).

Mate Guarding

The Mate Retention Inventory Short-form (Buss et al., 2008) measured mate guarding and retention. We used the Concealment of Mate, Derogation of Competitors, Resource Display, Sexual Inducements, Appearance Enhancement, Loving and Caring, Public Signals, and Intrasexual Threats subscales. Reliability alphas are acceptable, ranging from .64 to .83 and there is evidence of convergent validity with the full version of the Mate Retention Inventory. Scores range from 0 to 48. The menses mean for the sample was 32.06 (SD = 7.41). The fertility mean was 29.30 (SD = 8.31).

Analytic Plan

All analyses were conducted using SPSS with a two-tailed alpha set at .05. We used Pearson correlations to measure gender differences and inter-partner correlations on relationship satisfaction, mate guarding, and jealousy. We conducted dependent t-tests to determine changes in jealousy, mate guarding, and relationship satisfaction between menstruation and days of peak fertility. Finally, we conducted two multiple regression models to examine how two variables (i.e., mate guarding and jealousy) predicted scores on the dependent variable, relationship satisfaction. Given mate guarding is related to jealousy and can be the behavioral manifestation of the jealousy emotion (Lyons, 2019), multiple regression models were selected to examine the relative contribution of each variable. The first model used the mean relationship satisfaction scores reported during menstruation as the dependent variable and the mean mate guarding and jealousy scores reported during menstruation as the two independent variables. The second model used the mean relationship satisfaction scores reported during the peak fertility days as the dependent variable and the mean mate guarding and jealousy scores reported during the peak fertility days as the two independent variables.

Results

Correlational Analysis

Correlational analysis showed both partner's relationship satisfaction (menses r = .56, p < .01; fertile phase r = .43, p < .01), mate guarding (menses r = .36, p < .05; fertile phase r = .31, p < .05), and jealousy scores (menses r = .49, p < .01; fertile phase r = .31, p < .05) were all positively correlated regardless of fertility status. For women, their own mate guarding (r = .36, p < .01) and jealousy (r = .30, p < .01) are positively related to their relationship satisfaction during menstruation. When women are in their peak fertility days, their mate guarding (r = .34, p < .05) scores are positively related to their relationship satisfaction. For men, when their partner menstruates, his relationship satisfaction and her mate guarding behavior are positively related (r = .31, p < .05). For men, their mate guarding behaviors were positively related to their relationship satisfaction when their partner was in her fertile phase (r = .32, p < .05).

t-Tests

A series of dependent t-tests were conducted to determine changes in couple dynamics across the menstrual cycle. No significant changes were observed regarding relationship satisfaction and jealousy. However, for both men and women changes in mate guarding behaviors were observed with mate guarding reducing during the fertile phase. A dependent t-test was conducted to compare relationship satisfaction during menses and fertility phases. There was no significant change in relationship satisfaction during menses M = 22.34, SD = 2.67 and the fertile phase M = 22.35, SD = 2.84, t(82) = −.96.

A dependent t-test was conducted to compare jealousy during menses and fertile phases. There was no significant change in jealousy menses M = 42.48, SD = 4.326 and fertile phase M = 42.52, SD = 4.87, t(83) = −.120. A dependent t-test was conducted to compare mate guarding during menses and fertile phases. There was a significant change in mate guarding menses M = 32.20, SD = 6.97 and fertile phase M = 29.30, SD = 8.31008, t(83) = 5.60, d = .611.

Regression Analysis

Model 1

Prior to executing a multiple regression analysis, data was checked for outliers, missing data, and assumption violations. Outliers were removed from the data and missing data was not included in the results. Assumptions were not violated (multicollinearity, sample size, normality, linearity, and homogeneity of variance among the residuals).

A multiple regression analysis was conducted with mean relationship satisfaction during menses as the dependent variable and mean mate guarding and jealousy during menses as the independent variables. In this regression, 12.7% of the variance was explained by the model (R = 0.36, p < .01). The unstandardized regression coefficient (β1) for jealousy equaled .149 (p = .013), t(98) = 2.54 and (β2) for mate guarding equaled .100 (p = .006, t(98) = 2.80) with the intercept equaled to 12.74 (p < .001, t(98) = 4.60). The variance accounted for (R²) equaled 12.7(adjusted R² = .10.9), which was statistically significant, F (2, 96) = 6.965, p < 0.001.

Model 2

Prior to executing a multiple regression analysis, data was checked for outliers, missing data, and violation of assumptions. Outliers were removed from the data and missing data was not included in the results. Assumptions were not violated (multicollinearity, sample size, and normality, linearity, and homogeneity of variance among the residual).

A multiple regression analysis was conducted with mean relationship satisfaction during peak fertility as the dependent variable and mean mate guarding and jealousy during ovulation as the independent variables. In this regression, 12% of the variance was explained by the model (R = 0.346, p < .006). The unstandardized regression coefficient (β1) for jealousy equaled .062 (p = .321), t(83) = .998, and (β2) for mate guarding equaled .118 (p = .002), t(83) = 3.225 and the intercept equaled 16.179 (p < .001), t(83) = 5.502. The variance accounted for (R²) equaled .120 (adjusted R² = .098), which was statistically significant, F(2, 81) = 5.506, p < .006.

Discussion

Findings show couples’ jealousy, mate guarding, and relationship satisfaction scores were correlated. Similar jealous and mate guarding behaviors may be demonstrating an established phenomenon known as assortative mating, or the process wherein individuals are more likely to select mates with similar phenotypes or psychological profiles (Harper & Zietsch, 2025). Consistent with existing literature, couples in this sample demonstrated aligned relationship satisfaction perspectives (Meyer et al., 2024). During menstruation, women's mate guarding and jealousy scores were positively related to their relationship satisfaction. This suggests protective behaviors (i.e., mate guarding) and emotions (i.e., jealousy) may serve as indicators of relationship happiness and a committed desire to maintain that bond. During peak fertility days, only women's mate guarding behaviors, not jealousy, were positively related to their relationship satisfaction. This divergence may show a cycle-contingent shift in self-assurance reflected in the relationship, as the evidence shows women exhibit more confidence during ovulation (Schleifenbaum et al., 2021).

For men, relationship satisfaction is positively related to his partner's mate guarding during menses. This may result from men noticing subtle changes in their partner's relationship protective behaviors. In turn, men may feel more appreciated, increasing their relationship satisfaction (Mostova et al., 2022). For men, their mate guarding behaviors were positively related to their own relationship satisfaction when their partner was in her peak fertility phase. These findings are consistent with previous research demonstrating that men adapt their behaviors when their partner ovulates (Haselton & Gildersleeve, 2011). Specifically, when men value their partner and are happy in their relationship, they are more like to display mate guarding behaviors (Salkicevic et al., 2014).

Across genders, jealousy and relationship satisfaction scores remained unchanged regardless of fertility status. This may be showing that couples relationship dynamics are relatively stable. The sample couples had been together on average for almost 8 years. Couples may have endured relationship challenges and developed a stable relationship foundation built on love and resilience. Surprisingly, we observed fewer mate guarding behaviors during peak fertility compared to menstruation. The reduction in mate guarding may indicate couples are comfortable and trust one another. The increase in mate guarding behaviors during menses could demonstrate couples’ behavioral commitment to one another. Menses may also be a time when women physically feel worse and male partners may want to ensure their partner feels loves and appreciated during what could be a hard time. In return, women may be matching their partners’ mate guarding behaviors through a synchronous process (Sharon-David et al., 2019).

During menses, jealousy and mate guarding behaviors predicted relationship satisfaction whereas during peak fertility days, only mate guarding behaviors predicted relationship satisfaction. These findings could show a compounded effect. Affiliation behaviors showing relationship investment may be needed when a woman is menstruating. Whereas, during fertility, relationship security is established and thus, the emotional experience of jealousy is not warranted to demonstrate love for a romantic partner. It is surprising that jealousy and mate guarding behaviors were associated with higher related relationship satisfaction as these behaviors are often perceived as controlling behaviors and detrimental to romantic relationships (Degiuli et al., 2023). The correlation between mate guarding and jealousy could exhibit a paradoxical experience where jealousy and mate guarding behaviors are interpreted as a demonstration of love. When a partner expresses jealousy in manageable amounts, this may provide their partner an opportunity to express their care and relationship commitment. Mate guarding behaviors, albeit in small doses, may be interpreted as the partner not wanting to lose their partner. Additionally, given the situation, a romantic partner may appreciate the affiliative behaviors. For example, if a partner is experiencing unwanted attention from a potential suitor, they may appreciate their partner joining with them to affirm their relationship. Yet, it is important to note that our sample reported on average lower jealousy and mate guarding scores. This may demonstrate the behaviors and feelings are present, but not to the extent that they are controlling and detrimental to the relationship.

Ovulatory Shift Hypothesis Theory

The OSH indicates that women exhibit greater short-term attraction to genetically fit men during the fertile window, while men are expected to increase mate-retention efforts when their partner is fertile (Gangestad & Thornhill, 2008; Gildersleeve et al., 2014). Critics argue that when these studies are done with stronger methods that account for larger sample sizes and confirm hormone levels, these effects are minimized. They suggest that some of the earlier positive results may have been due to studies with significant findings being published, researchers having flexibility in how the data was analyzed, and imprecise fertility estimates (Harris et al., 2014; Wood & Carden, 2014). Recent longitudinal research has not found consistent evidence suggesting that women's preference for their partners changes (van Stein et al., 2019).

The present findings suggest a different model is warranted for established couples. Jealousy and relationship satisfaction did not change based on women's fertility status, which counters the predictions of the OSH: that men would feel more threatened by potential rivals when their partner's fertility is high (Gangestad & Thornhill, 2008). Additionally, our results indicated that mate-guarding behaviors were lower during peak fertility than during menses, again opposite to the expectations of the OSH. During menstruation, both jealousy and mate-guarding were linked to higher satisfaction, whereas during ovulation only mate-guarding was linked to higher relationship satisfaction. For men specifically, when their partner was menstruating, his relationship satisfaction was positively correlated to her mate guarding (a potential appreciation effect), and when she was in her fertile window, his mate-guarding was positively related to his satisfaction.

Women may feel physically or emotionally worse during menstruation, so these protective behaviors may be interpreted as partnerly love, which the OSH does not account for. In long-term relationships, these behaviors might show that partners care, support, and feel close to one another rather than being about protecting the relationship from a threat or being a display of controlling, possessive behavior. Women's increased confidence and self-perceived attractiveness near ovulation may also help explain why jealousy is not needed to support relationship satisfaction during that phase (van Stein et al., 2019). This idea is supported by large studies where couples kept daily diaries; they demonstrated that men do not typically notice when their partner is most fertile and do not change their jealousy or mate-guarding behaviors in response (Schleifenbaum et al., 2022). Critics have also concluded changes across the menstrual cycle do not typically have lasting effects on the quality of long-term relationships, challenging the OSH and the idea that fertility during ovulation causes women to prefer genetically superior men (Wood & Carden, 2014).

Limitations and Future Research

Our longitudinal study was able to collect data across romantic partners for a menstrual cycle with established couples. Our findings are limited to populations homogenous to our sample. Unfortunately, our sample was small and lacked significant representation from gender, sexual, and racial minorities. Additionally, our small sample limited our ability to run dyadic analysis to examine how partner's influence one another's behavioral outcomes. Finally, we relied on self-report measures for our data including determining if one partner was menstruating or fertile. It is our hope that the participants were accurate in their reports. Self-report is biased to how participants want to project themselves. As both romantic partners participated in this study, participants may have also been concerned about how their partner may perceive their report.

Future studies should attempt to replicate our findings. There is limited research examining how fertility status affects romantic partners, and we cannot know if additional research would reach the same conclusions as our results. Future research should also track changes in couple dynamics across multiple menstrual cycles to establish longitudinal stability. Finally, future research should include same sex couples in the study. Particularly, research with lesbian couples where two partners might be menstruating and ovulating concurrently could add depth to the literature about couple dynamics and fertility.

Clinical Implications

Our findings noting behavior changes throughout the menstrual cycle, such as increased mate guarding, increased confidence (Schleifenbaum et al., 2021) and male adaptations (Mostova et al., 2022), indicate the need to incorporate biological cycles into clinical assessments to promote client biopsychosocial awareness. Providing clinical psychoeducation on cycle changes and tracking for coupled clients could empower couples to track cycles and increase their awareness of changes. With increased awareness, counselors should consider encouraging coupled partners to discuss their changing needs across time, rather than attributing shifts to relationship problems. Another clinical implication based on the study's findings that jealousy and mate guarding behaviors were associated with higher related relationship satisfaction indicates the need for counselors to reframe jealousy and mate guarding as an adaptive process. Although jealousy and mate guarding have previously been perceived as inherently maladaptive in romantic relationships (Degiuli et al., 2023), the current study shows increased relationship satisfaction. These findings may suggest that counselors should avoid conceptualizing jealousy as negative or pathological, and instead assess jealousy intensity, intent, impact on partner autonomy, and the couple's interpretation on the jealousy.

Furthermore, counselors should guide couples to translate jealousy into vulnerable communication as jealousy may provide access to deeper relational themes such as attachment insecurity, fear of abandonment, or need for validation. Counselors could help couples distinguish between jealousy and coercive or controlling behaviors. By exploring the meaning a couple assigns to behaviors, counselors can promote increased understanding of intent of behaviors and deeper emotional processes. Finally, as couples may increase mate guarding during menstruation, counselors could translate these behaviors to anytime when couples are physically or emotionally worn out. During times of biopsychosocial stress, counselors should encourage partners to increase supportiveness and devotion. For committed couples, counselors can create interventions to promote opportunities for couples to demonstrate their fidelity to one another.

Footnotes

ORCID iD

Dixie Meyer

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Saint Louis University.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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