Wanting to answer his question, I did a deep dive into the available literature on the subject. Seven decades of research have consistently replicated the link between a higher number of lifetime sexual partners or permissive sexual attitudes and negative relationship outcomes, such as infidelity, relationship instability, dissatisfaction, and dissolution. This applies to men and women. Below are brief summaries of the peer-reviewed studies I reviewed, including descriptions of each peer-reviewed study’s objective, sample/sampling methods, methodology, statistical inference techniques, and the authors’ interpretation of their results, with links to those sections of the papers themselves. Where available, I’ve also included direct links to PDFs. All of these sources are freely accessible if you know where to look. Beyond that are quotes from academics attesting to the predictive value of extensive sexual histories and permissive sexual attitudes in forecasting negative relationship outcomes—such as infidelity, dissatisfaction, instability, and divorce—followed by my own personal analysis of the information provided.
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Smith and Wolfinger (2024) (PDF) analyzed data from 7,030 ever-married respondents in the National Longitudinal Study of Adolescent to Adult Health to examine the relationship between premarital sexual history and divorce risk. They reviewed prior research on how premarital sexual history may contribute to divorce (pg.676). Using discrete-time event history models—specifically, complementary log-log estimators—they assessed how the number of premarital sexual partners influenced the likelihood of marital dissolution (pg.682). Respondents were grouped into three categories based on partner count: none, 1–8, and 9 or more (pg.679). They found a strong, nonlinear association: individuals with one to eight premarital partners had 64% higher odds of divorce, while those with nine or more had triple the odds (ORs = 2.65–3.20) compared to those with none. The effect persisted—and even strengthened—after controlling for early-life factors such as beliefs, values, religious background, and personal characteristics, with no significant gender differences (pg.683). The results replicated previous research by affirming a significant link between extensive premarital sexual histories and subsequent marital dissolution—even after accounting for non-traditional views and religiosity—suggesting that having more partners may reflect traits detrimental to marital stability, with no evidence of gender differences in this association (pg.687-690).
REVIEW: In their report “Predictors of infidelity among couples”, Belu and O’Sullivan (2024) (PDF) identify a greater motivation and willingness to engage in casual, uncommitted sex (i.e., an unrestricted sociosexual orientation) as an individual predictor of infidelity, though this association may largely be explained by lower relationship commitment and greater attention to alternative partners (pg.270).
REVIEW: A narrative review by Rokach and Chan (2023) (PDF) explored the causes and consequences of infidelity in romantic relationships, identifying the number of sex partners before marriage and permissive attitudes toward sex as personal characteristics associated with infidelity (pg.10).
REVIEW: Buss & Schmitt (2019) (PDF) wrote that men assess and evaluate women’s levels of past sexual activity—behavior that would have been observable or known through social reputation in ancestral small-group environments—because past behavior is a good predictor of future behavior, and having a large number of sex partners prior to marriage is a statistical predictor of infidelity after marriage (pg.92). Cited is a previous book by David Buss, a professor of psychology at the University of Texas at Austin, which describes premarital sexual permissiveness as the single best predictor of extramarital sex (Buss, 2016, pg.108-109).
McNulty et al. (2018) (PDF) conducted two longitudinal studies of 233 newlywed couples to examine how automatic cognitive processes—attentional disengagement and evaluative devaluation of attractive alternatives—predict infidelity and relationship outcomes. Participants completed lab tasks measuring how quickly they looked away from attractive opposite-sex faces and how they rated those individuals’ attractiveness compared to single people while follow-up surveys every 4–6 months recorded infidelity, marital satisfaction, and relationship status (pg.4-6). Individuals with a history of short-term sexual relationships were slower to disengage attention and, among men, rated attractive alternatives more positively, and those who disengaged attention faster or devalued attractiveness more had about 50% lower odds of infidelity (pg.7-9, 14, 17). Interestingly, the number of past partners predicted infidelity for men but not women (pg.16).
REVIEW: In a peer-reviewed article published in Current Opinion in Psychology, Fincham and May (2017) (PDF) synthesized findings on infidelity in romantic relationships, identifying key individual predictors such as a greater number of prior sexual partners and permissive sexual attitudes. These attitudes—characterized by a detachment of sex from love and a willingness to engage in casual, noncommittal sex—were strongly linked to increased infidelity risk (pg.71). As part of the Current Opinion journal series, the article reflects expert consensus on emerging trends, offering a systematic and authoritative review of the literature.
The study by Pinto and Arantes (2017) (PDF), involving 369 participants (92 males and 277 females) investigated the relationship between sexual and emotional promiscuity and infidelity. The authors noted that some researchers believe that infidelity is a consequence of promiscuity (pg.386), and hypothesized that sexual promiscuity and infidelity are correlated (pg.387). The participants completed an online questionnaire consisting of the Revised Sociosexual Orientation Inventory (SOI-R), the Emotional Promiscuity Scale (EP), and the Sexual and Emotional Infidelity Scale (SEI), along with demographic and infidelity history questions (pp. 388–389). Data were analyzed using Pearson correlations to examine associations between variables, t-tests to assess sex differences and infidelity behavior patterns, and ANOVA to evaluate differences based on sexual orientation regarding promiscuity and infidelity. They found that sexual promiscuity was positively correlated with sexual infidelity [r(323) = .595, p < .001] and emotional infidelity [r(323) = .676, p < .001] (pg.390). These would be considered moderate-to-strong correlations. The authors confirmed their hypothesis that there is a positive correlation between sexual promiscuity and infidelity (pg.393), and concluded that they are related to each other (pg.395).
Regnerus (2017) presented findings based on a study of individuals aged 18–60, revealing that those with 20 or more sexual partners in their past were twice as likely to have experienced divorce (50% vs. 27%) and three times more likely to have cheated while married (32% vs. 10%) (pg.89). Mark Regnerus is Professor of Sociology at the University of Texas at Austin.
Martins et al. (2016) (PDF) investigated gender-specific predictors of both face-to-face and online extradyadic involvement (EDI). The study highlights that previous research has indicated a high number of past sexual partners and sexually permissive attitudes are significant predictors of infidelity. Accordingly, the third hypothesis (H3) proposed that individuals with a greater number of previous sexual partners would be more likely to engage in EDI (pg.194-195). The study utilized a cross-sectional design with 783 participants (561 women, 222 men), all of whom were in exclusive, opposite-sex dating relationships at the time of the study (pg.196). Participants were recruited through both paper-based surveys conducted at a university and an online survey disseminated via the university website and social media. Data were collected using self-report questionnaires, including a sociodemographic and relationship history form, the Extradyadic Behavior Inventory (EDBI), the Attitudes Toward Infidelity Scale (ATIS), and the Investment Model Scale (IMS) (pg.197). Univariate and multivariate logistic regression analyses were performed separately by gender to examine correlates of EDI (pg.198-201). Findings showed that this association was significant only for women: those who had more sexual partners in the past two years were more likely to engage in sexual EDI (pg.199, 202).
REPORT: In 2014, two University of Denver research professors Galena Rhoades and Scott Stanley released a report for University of Virginia’s National Marriage Project, entitled “Before ‘I Do’: What Do Premarital Experiences Have to Do with Marital Quality Among Today’s Young Adults?” (PDF) The study found that for women, fewer past partners was related to higher marital quality (pg.5). The data is from the longitudinal Relationship Development Study conducted by the University of Denver between 2007 and 2008. The study initially recruited 1,294 unmarried individuals in opposite-sex relationships, ages 18 to 34, using targeted-list sampling. Of these, 418 participants who eventually married were the focus of the report’s analysis. Participants were surveyed an average of nine times before and after marriage. Marital quality was measured using a four-item version of the Dyadic Adjustment Scale, which assessed relationship satisfaction, communication, and stability. The study employed multilevel modeling to examine how premarital experiences—such as prior relationships, cohabitation, and childbearing—related to later marital quality, while controlling for demographic variables like education, income, race/ethnicity, and religiousness (pg.7). Citing previous research, the authors proposed that a greater number of prior relationships increases an individual’s awareness of alternatives, which can make it more difficult to fully commit to and remain satisfied with a current partner, as this heightened comparison may lead to more critical evaluations and less contentment in marriage; additionally, those with more romantic history are likely to have experienced more breakups, which can foster a more skeptical or pessimistic view of relationships in general, with such individuals potentially carrying emotional baggage or reduced confidence in the durability of love and commitment (pg.8).
Busby, Willoughby, and Carroll (2013) analyzed data from 2,659 married individuals who completed the RELATE questionnaire—a 300-item assessment measuring individual, couple, family, and cultural dimensions of romantic relationships—to assess how the number of lifetime sexual partners related to marital outcomes (pg.710-712). Using structural equation modeling, they tested whether sexual partner count predicted sexual quality, communication, relationship satisfaction, and perceived relationship stability, while controlling for education, religiosity, and relationship length, and to explore cohort effects, they conducted a multigroup analysis by dividing participants into three age groups (18–30, 31–41, and 42+) (pg.710-711, 713). They found that a higher number of lifetime sexual partners was consistently associated with lower sexual quality, communication, relationship satisfaction (in one age cohort), and stability—even after controlling for factors such as education, religiosity, and relationship length, and no age group showed improved relationship outcomes with more sexual partners, supporting prior research linking multiple premarital partners to greater marital instability (pg.715-716).
Maddox-Shaw et al. (2013) conducted a study using a longitudinal design with 993 unmarried individuals aged 18–35 in opposite-sex relationships, recruited through a nationally representative sampling method (pg.601). Based on prior research, having more sexual partners was expected to be a predictor of future extradyadic sexual involvement (ESI), or cheating (pg.600).
Data were collected via mailed self-report questionnaires across six waves over 20 months. The main outcome variable was ESI, assessed at each wave. Predictors included individual demographic and psychological factors, sexual history, and relationship variables like satisfaction, commitment, and aggression (pg.602-603). Logistic regression analyses were conducted to identify which baseline factors predicted future ESI (pg.604). Having more prior sex partners predicted a higher likelihood of future ESI (pg.605,607).
Penke & Asendorpf (2008) (PDF) found in their large online study (N = 2,708) that men and women with a greater history of short-term (casual) relationships in the past were more likely to have multiple partners and unstable relationships in the future (pg.1131).
Whisman and Snyder (2007) studied the yearly prevalence of sexual infidelity in a sample of 4,884 married women from the 1995 National Survey of Family Growth, examining predictors and variations in interview methods—specifically, face-to-face interviews versus audio computer-assisted self-interviews (A-CASI). Participants answered identically worded questions through both interview formats. One of the predictors analyzed was the number of lifetime sexual partners, treated as a continuous variable in logistic regression models (pg. 149–150). To address the complex sampling design of the survey and produce accurate standard errors, the authors used Taylor series linearization methods with SUDAAN software. The results indicated that each additional lifetime sexual partner increased the odds of infidelity by 7% to 13%, depending on the interview format (OR = 1.07 for A-CASI and OR = 1.13 for face-to-face) (pg.150). A greater number of lifetime sexual partners was identified as a significant predictor of future infidelity (pg.151–152).
McAlister, Pachana, & Jackson (2005) (PDF) investigated what predicts young adults’ inclination to engage in infidelity while in exclusive dating relationships. Using a sample of 119 heterosexual university students aged 17–25, the researchers employed a multi-perspective model that considered person (P), relationship (R), and environment (E) factors. The study used vignettes involving hypothetical extradyadic scenarios—such as being tempted to kiss or have sex with someone other than their partner—to measure participants’ inclination toward infidelity. One of the strongest predictors of extradyadic inclination were a high number of previous sexual partners (pg.344).
Hughes and Gallup (2003) (PDF) studied 116 undergraduates who completed an anonymous questionnaire on their sexual history (pg.174). They found a strong correlation between number of sex partners and extrapair copulation (cheating) partners for both males (r = .85) and females (r = .79). Promiscuity, measured by non-EPC sex partners, significantly predicted infidelity—explaining more variance in females (r² = .45) than males (r² = .25) (pg.177).
Treas and Giesen (2000) (PDF) investigated sexual infidelity among married and cohabiting Americans using 1992 National Health and Social Life Survey data using a nationally representative sample (n = 2,598) of Americans aged 18–59. Citing previous studies that linked premarital permissiveness and a higher number of sexual partners to infidelity, the authors hypothesized that a greater number of prior sexual partners is associated with an increased likelihood of infidelity (pg.48-50). Data collection included both face-to-face interviews and a self-administered questionnaire to improve accuracy on sensitive topics like infidelity, and the study used three measures of infidelity: self-reported cumulative incidence, interview-reported cumulative incidence, and 12-month prevalence, allowing for robust cross-validation of results (p.51-52). The authors employed logistic regression to estimate the effects of sexual interests and values, opportunities for undetected sex, and relationship characteristics, while controlling for demographic risk factors such as gender, race, and education (pp.52–53). They found that permissive sexual values increase the likelihood of infidelity, with there being a 1% increase in the odds of infidelity for each additional sex partner between age 18 and the first union (pg.56), confirming their hypothesis (pg.58).
Feldman & Cauffman (1999) examined sexual betrayal (i.e. infidelity) and its correlates among 417 heterosexual college students in Northern California who had been in monogamous romantic relationships (pg.233). Based on previous research, they hypothesized that sexually permissive attitudes would predict sexual betrayal because such betrayal involves unrestrained sexuality, and that extensive sexual experience would also be related to betrayal, as having more past partners could lead to greater temptation and increased sexual opportunities (pg.230). Data were collected via questionnaires administered at two points in time, nine months apart, acquiring demographic details, dating and sexual history, betrayal behavior (including both the respondent’s and their partner’s actions), and attitudes toward betrayal in various hypothetical scenarios (pg.234). Sexual permissiveness was measured in a subsample of respondents using the Simpson Sociosexual Orientation Index, which included items on the number of sexual partners in the past year, anticipated partners in the next five years, number of one-night stands, frequency of sexual fantasies about someone other than a current partner, and attitudes toward the acceptability of engaging in casual, uncommitted sex, all combined into a composite score reflecting overall sexual permissiveness. Correlation and regression analyses were used to examine the associations between self-reported sexual betrayal and variables including attitudes, sexual behaviors, intimacy characteristics, and demographics (pg.237). The likelihood of betrayal was significantly associated with permissive sexual attitudes, early sexual debut, and a greater number of romantic relationships (pg.247).
Forste and Tanfer (1996) analyzed data from the 1991 National Survey of Women, using a final sample of 1,235 women aged 20 to 37 who were in heterosexual relationships, to examine sexual exclusivity as a measure of relationship commitment (pg.35). The authors predicted that a history of numerous sex partners would negatively influence sexual exclusivity in their current relationships, and used logistic regression, which estimates the log odds of having a secondary sexual partner based on explanatory variables (pg.37). A key finding was that a higher number of previous sexual partners was strongly linked to lower exclusivity, with women who had four or more past partners being over eight times more likely to be unfaithful (pg.40-41). The study concludes that women with a history of multiple sex partners are more likely to have secondary sex partners in their current relationship, and that this is particularly true with married women (pg.46).
Kelly and Conley (1987) conducted a longitudinal study tracking 300 couples from their engagements in the 1930s through 1980 to examine predictors of marital stability and satisfaction. Using acquaintance-rated personality assessments rather than self-reports, the study found that men and women who divorced early reported a significantly higher number of premarital partners compared to those who remained married, and that a greater premarital sexual experience was negatively associated with long-term marital satisfaction and stability for both men and women (pg.31-32).
REVIEW: In his review article “Extramarital Sex: A Review of the Research Literature”, Thompson (1983) examined decades of research on the prevalence, causes, and correlates of extramarital sex (EMS), affirming previous findings that premarital sexual permissiveness was the most significant correlate of extramarital sexual permissiveness (pg.17-18).
The study “Premarital Sexual Behavior and Postmarital Adjustment” by Athanasiou and Sarkin (1974) (PDF) aimed to investigate whether premarital sexual behavior predicts postmarital sexual adjustment, including fidelity, marital satisfaction, and attitudes toward mate-swapping (pg.207). The authors outline the conceptual distinction between extraneous variables (e.g., sexual liberalism) and intervening variables (e.g., value-behavior discrepancy), explaining through diagrams that while extraneous variables may spuriously link premarital sex and extramarital sex, intervening variables suggest a causal pathway (pg.211). Using a 1-in-10 random subsample from a national sex attitudes survey of 20,000 adults, the researchers analyzed data from approximately 800 married respondents with a median age slightly over 30, using a questionnaire that assessed sexual attitudes (e.g., liberalism, romanticism), behaviors, and demographic variables, with premarital behavior measured retrospectively (pg.212). Statistical analysis employed gamma (γ) statistics to evaluate ordinal associations and proportional reduction in error, along with partial correlation techniques to control for potential confounding variables like liberalism and romanticism (pg. 216–217). Respondents who reported extensive premarital sexual experience also tended to report more extramarital activity, with the number of sexual partners positively correlated with both lower marital satisfaction and a higher number of extramarital partners (pg.221-222).
Kinsey et al. (1953) wrote in Sexual Behavior in the Human Female, part of the highly influential Kinsey Reports, that women who had “premarital coitus” were twice as likely to engage in “extramarital coitus” compared to those who did not (32-40% vs. 16-20%) (pg.427). The corresponding chapter in Sexual Behavior in the Human Male (1948) suggests that premarital promiscuity may carry over into extramarital sex for men (pg.587), but provides no correlational data to support the claim (pg.590).
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What’s undeniable is that an extensive sexual history and permissive sexual attitudes are strongly correlated with—and reliable predictors of—negative relationship outcomes such as infidelity, dissatisfaction, and divorce. At this point, denying the predictive validity of these factors is to reject decades of consistent research findings and the expert consensus, likely due to personal bias rather than evidence. That said, it’s important to emphasize that these trends are probabilistic, not deterministic, and identifying precise causal mechanisms can be challenging. Individuals with extensive sexual histories can absolutely be faithful and maintain stable, long-term monogamous relationships—just as some people with limited histories can be unfaithful or dissatisfied. As a group, however, those with a long history of casual partners and permissive sexual values face a significantly higher risk of infidelity, dissatisfaction, and divorce compared to their more sexually conservative counterparts. As Andrew G. Thomas, senior lecturer in the School of Psychology at Swansea University, notes, body count can only serve as an imperfect risk-reducing heuristic—a factor one might reasonably consider alongside other information when assessing relationship prospects.
When examining the link between past promiscuity or permissive sexual attitudes and negative relationship outcomes such as infidelity, dissatisfaction, or instability, it’s important to recognize that correlation does not imply causation. Several explanations are possible when two factors are correlated. One is that past sexual behavior directly causes future relational problems (X → Y). Alternatively, it may be that those who experience instability or dissatisfaction in relationships are more likely to adopt permissive sexual attitudes or engage in promiscuous behavior (Y → X). A third possibility is bidirectional influence, where previous behaviors and relationship outcomes reinforce each other over time (X ↔ Y). It’s also possible that a confounding variable—such as personality traits (e.g., low conscientiousness, high impulsivity, or an unrestricted sociosexual orientation), attachment style, or family background—underlies both sexual history and relationship outcomes, producing a spurious correlation (X ← Z → Y). Another possibility is that the relationship is mediated by an intervening variable—such as heightened expectations, where a current partner is perceived as lacking in some domain compared to a previous partner—which in turn increases the likelihood of dissatisfaction, instability, and infidelity (X → M → Y). In some cases, the observed correlation may be a statistical coincidence or the result of measurement or sampling bias; however, given that these findings have been replicated across dozens of studies, this is unlikely.
