The Why Have Sex? Questionnaire Short Form (YSEX-SF) is a 28-item self-report measure of sexual motivation for adults aged 18 years and over (Meston et al., 2020). It assesses the reasons a person has engaged in sex, capturing how frequently each of 14 distinct motivations has led them to have sexual intercourse across their past sexual experiences. For respondents who have not previously had sex, the measure instead assesses the likelihood that each motivation would lead them to have sex.
The YSEX-SF is a short form of the Why Have Sex? Questionnaire (YSEX?), considered the most comprehensive taxonomy of sexual motivations in the research literature (Meston & Buss, 2007). It produces a profile of 14 subscale scores rather than a single total score, and is used clinically to support formulation and feedback in sex therapy, relationship counselling, and general practice.
People have sex for far more varied reasons than the familiar ones of pleasure, procreation, and love. The research programme behind the instrument identified 237 distinct reasons (Meston & Buss, 2007). Which of these motivations drive a person’s sexual behaviour carries meaningful information about their sexual desire, relationships, and wellbeing, and making those motivations explicit gives clinicians a structured way to understand what underlies a client’s sexual behaviour.
The 14 subscales span physical, emotional, goal-oriented, and insecurity-related motivations for sex. Each is measured by two items.
The YSEX-SF was originally developed for research on sexual motivation and remains suited to that purpose. On NovoPsych it is applied clinically, chiefly to support formulation and feedback, rather than screening, diagnosis, or progress monitoring.
The measure can be used in sex therapy, relationship counselling, and general clinical practice wherever a client’s sexual behaviour, desire, or satisfaction is a focus of treatment. Its primary contribution is to formulation: the 14-subscale profile answers the question of what is driving a client’s sexual behaviour. A profile dominated by Duty/Pressure and Mate Guarding motivations tells a fundamentally different clinical story from one dominated by Pleasure and Love and Commitment motivations. The pattern of motivations across a profile can also clarify presentations involving mismatched desire, sexual dissatisfaction, or relationship insecurity.
The YSEX-SF supports psychoeducation and feedback conversations. The research behind the instrument documented a far wider range of sexual motivations than is typically assumed, and reviewing the profile collaboratively as part of treatment can normalise a client’s experience and open conversations that might not otherwise arise.
The measure provides a snapshot of the respondent’s motivational history rather than a measure of change over time. It functions closer to a structured screening of motivations than to an outcome measure, and is best used for formulation and feedback at a given point in care.
All 28 items have response options ranging from 1 (None of my sexual experiences) to 5 (All of my sexual experiences). Each of the 14 subscales is scored by summing its two items, giving subscale scores from 2 to 10. Higher scores indicate that a greater proportion of the respondent’s sexual experiences have been motivated by that reason.
No total score is computed, and the measure has no norms, percentiles, or clinical cut-offs. The clinical output is the 14-subscale profile. For respondents who have not had sex, the instructions direct them to rate the likelihood that each reason would lead them to have sex, and their profile is read as anticipated rather than experienced motivation.
| Subscale | Items | What it assesses |
|---|---|---|
| Stress Reduction | 1, 15 | Sex used to release frustration, anxiety, or stress. Higher scores may indicate that sex serves an emotion-regulation function. |
| Pleasure | 2, 16 | Sex motivated by physical enjoyment and desire. Typically among the most frequently endorsed motivations. |
| Physical Desirability | 3, 17 | Sex motivated by attraction to the other person’s appearance. The items refer to the person rather than a partner, reflecting that the measure covers casual and non-partnered sex. |
| Experience Seeking | 4, 18 | Sex pursued for novelty, adventure, or excitement. |
| Resources | 5, 19 | Sex exchanged for tangible gain such as money or favours. Elevated scores indicate that exchange-based motivations feature in the respondent’s experiences. |
| Reproduction | 6, 20 | Sex motivated by the desire to conceive. Scores are strongly context-dependent and interpreted in light of life stage and relationship circumstances. |
| Social Status | 7, 21 | Sex used to enhance reputation or standing. |
| Revenge | 8, 22 | Sex used to retaliate against a partner or get even with someone. Elevated scores may indicate unresolved relational conflict. |
| Practical | 9, 23 | Sex pursued for practical benefits. The two items span distinct content, one physical and one emotional, so reviewing them individually shows which is driving the score. |
| Love and Commitment | 10, 24 | Sex used to express love and feel connected. Low scores in a partnered respondent may be clinically informative about the relational function of sex. |
| Expression | 11, 25 | Sex used to mark special occasions or transitions, such as welcomes, farewells, and celebrations. |
| Self-Esteem Boost | 12, 26 | Sex used to feel better about oneself. Elevated scores may indicate that sexual activity is serving a self-worth regulation function. |
| Duty/Pressure | 13, 27 | Sex engaged in out of obligation or in response to pressure. Elevated scores can reflect experiences of sexual coercion. |
| Mate Guarding | 14, 28 | Sex used to keep a partner from straying. Elevated scores may indicate relationship insecurity or fear of abandonment. |
Each subscale score is accompanied by a frequency descriptor taken directly from the measure’s own response options. Because each subscale consists of two items scored from 1 (None of my sexual experiences) to 5 (All of my sexual experiences), the summed subscale score can be translated back into the corresponding response scale to aid interpretation. These descriptors are not part of the original scoring system, and provide a plain-language summary of how frequently each motivation has contributed to the respondent’s sexual experiences.
| Subscale score | Frequency descriptor |
|---|---|
| 2 | None of my sexual experiences |
| 3 to 4 | A few of my sexual experiences |
| 5 to 6 | Some of my sexual experiences |
| 7 to 8 | Many of my sexual experiences |
| 9 to 10 | All of my sexual experiences |
These descriptors are frequency labels rather than severity ratings or indicators of clinical significance. The clinical relevance of a given descriptor depends on the motivation being assessed and the respondent’s circumstances. A descriptor of Many of my sexual experiences may be expected for motivations such as Pleasure or Love and Commitment, whereas the same descriptor for Duty/Pressure may warrant further clinical exploration regarding possible coercion or unwanted sexual experiences.
The profile is interpreted relatively. The most clinically informative feature is which motivations are most and least frequent for the respondent, rather than the value of any single subscale in isolation. Considered together, the 14 subscale scores describe the overall shape of the respondent’s motivational profile.
Conceptually related subscales are often more informative in combination than any subscale considered alone. Representative examples include:
The Duty/Pressure items (I was pressured into doing it and I felt obligated to) can reflect experiences of sexual coercion. Where either item is endorsed above None of my sexual experiences, the report displays a note for the clinician showing both item responses, and adds a Duty/Pressure tag to the results dashboard. Clinicians are encouraged to review the individual item responses directly and follow up carefully to clarify the nature and context of these experiences.
Duty/Pressure is deliberately the only subscale carrying an automated clinician note. Elevations on Resources or Revenge can also carry clinical weight, but their meaning is more context-dependent, and they are left to the profile text and clinician review so the single high-stakes flag is not diluted.
The report presents a horizontal bar chart of the 14 subscale scores, one bar per subscale, in a fixed order on an axis from 2 to 10. Five shaded vertical bands behind the bars mark the frequency-descriptor regions (None, A few, Some, Many, and All), deepening in shade from left to right, so each bar’s length can be read as its frequency descriptor and the overall shape of the profile is visible at a glance.
The chart shows the profile for the current administration. Repeat administrations regenerate the single-administration profile. No longitudinal score-tracking graphs are produced, consistent with the measure’s snapshot design.
The original taxonomy for the 142-item YSEX? was developed in two stages (Meston & Buss, 2007). First, 444 participants nominated reasons for having sex, producing 237 distinct reasons. These were administered to 1,549 undergraduate students, and factor analyses yielded a hierarchical structure of four broad factors (Physical, Goal Attainment, Emotional, and Insecurity reasons) comprising 13 subfactors. The long-form instrument demonstrated strong internal consistency, with alphas exceeding .85 for each factor score.
The YSEX-SF was developed by Meston and colleagues from this same dataset (Meston et al., 2020, Study 1). The two most representative items for each subscale were selected using the original factor loadings combined with structured consensus judgements of conceptual fit. Where the original items were too specific to represent a subscale in two items, broader composite items were written. Two structural changes were made: the items concerning conception were separated from the Resources subscale into a new Reproduction subscale, and the Utilitarian subscale was renamed Practical. The result is a 28-item instrument with 14 subscales of two items each, an item reduction of just over 80 percent, that maintains the original instrument’s sound psychometric properties.
No standalone official copy of the YSEX-SF exists. The instrument’s first author has confirmed that the short form is administered by presenting the 28 retained items with the full-length YSEX? instructions and response options (C. M. Meston, personal communication, July 22, 2026). This is how NovoPsych presents it.
Internal consistency was assessed in a validation sample of 223 United States adults recruited online (ages 19 to 76, median 33; Meston et al., 2020, Study 2). The two-item subscale alphas ranged from .42 to .93, with an average of .74. Reliability was strongest for Reproduction (α = .93), Mate Guarding (α = .82), Resources (α = .81), Stress Reduction (α = .80), and Physical Desirability (α = .80), and acceptable for most remaining subscales, including Love and Commitment (α = .78), Social Status (α = .76), Experience Seeking (α = .75), Duty/Pressure (α = .75), Self-Esteem Boost (α = .74), and Revenge (α = .70). Pleasure (α = .68) and Expression (α = .62) showed more modest internal consistency, and Practical was the weakest subscale (α = .42), reflecting its two items spanning distinct physical and emotional benefits.
Because Cronbach’s alpha rises with the number of items, two-item subscales tend to produce lower coefficients than longer scales. These values should be read with the short scale length in mind rather than as evidence of weak items.
A confirmatory factor analysis in the validation sample (N = 218) supported the 14-factor structure, with acceptable model fit (CFI = 0.91, TLI = 0.86, RMSEA = 0.070, 90% CI [0.061, 0.078]) and standardised item loadings ranging from .52 to .92, excluding the variance-constrained Reproduction item whose corrected loading is reported as 1.00. The initial solution produced a negative residual variance (a Heywood case) for one Reproduction item (I wanted to have a child), resolved by constraining that item’s residual variance to be above zero with no meaningful loss of fit.
The 14 factors are modelled as correlated dimensions, consistent with the observation that reasons for having sex are not mutually exclusive. A person can have sex both out of obligation and to feel connected to their partner.
Cross-form validity between the YSEX-SF and the full-length YSEX? was generally strong (Meston et al., 2020, Study 2). Twelve of the 14 subscales correlated between r = .61 and r = .85 with their long-form counterparts. The Practical subscale correlated moderately with the long-form Utilitarian subscale (r = .43), reflecting the substantial condensing of that subscale’s content, and the new Reproduction subscale correlated moderately with the long-form Resources subscale from which its items were drawn (r = .39), consistent with its deliberate isolation as a distinct construct.
Construct validity was supported by theoretically coherent associations with personality and sexual-strategy measures. Higher scores on all three Dark Triad traits (Machiavellianism, narcissism, and psychopathy) were associated with more frequent Social Status, Revenge, and Mate Guarding motivations in both men and women. Love and Commitment showed no association with any Dark Triad trait in either gender, supporting the discriminant validity of the profile. Sociosexual orientation (openness to uncommitted sex) was associated with more frequent Revenge motivations in both genders, and with less frequent Love and Commitment motivation in women.
Gender differences on the YSEX-SF were small. Men scored higher than women on the three largest differences in motivation: Physical Desirability (d = 0.37), Social Status (d = 0.35), and Experience Seeking (d = 0.33). The largest difference on which women scored higher was Love and Commitment (d = 0.27). None of these differences remained statistically significant after correction for multiple comparisons (Meston et al., 2020). Scores are therefore interpreted without reference to gender.
NovoPsych does not calculate YSEX-SF percentiles. The only available normative data come from the validation sample of 223 United States adults recruited online, reported separately by gender, with pronounced floor effects on several subscales because most respondents endorse None of my sexual experiences for motivations such as Resources, Revenge, and Reproduction. Percentiles derived from that sample would imply a reference comparison and a degree of precision the data do not support. The measure also has no clinical cut-offs anywhere in the literature. Interpretation therefore rests on the frequency descriptors and the shape of the profile.
Sexual difficulties can sometimes be better understood once the motivations behind sexual behaviour are considered. Two clients with identical presentations, for example low desire, can have very different profiles: one may have sex mainly out of obligation and relationship insecurity, while the other’s profile centres on pleasure and connection that has recently declined. The YSEX-SF makes these patterns more explicit, helping the clinician and client build a shared formulation of what role sex plays in the client’s life and identify areas that may warrant further exploration.
No. The research behind the YSEX-SF identified over two hundred distinct reasons people have sex, spanning pleasure, love, curiosity, comfort, celebration, and many others, and most people endorse a mix. The measure describes how frequently each motivation has featured in the respondent’s experiences without judging any of them as necessarily positive or negative.
Some patterns may still warrant further clinical exploration. Sex motivated primarily by distress reduction or self-esteem enhancement may suggest an opportunity to explore broader coping strategies or emotional functioning.
Frequent sex out of obligation or pressure can range from consensual but unwanted sex within a relationship through to experiences of sexual coercion. The NovoPsych report flags elevated Duty/Pressure scores for the clinician, and follow-up may be warranted: clarifying who or what the pressure comes from, whether it is current or historical, and how the client feels about these experiences. Depending on what emerges, treatment might focus on relational communication and consent, assertiveness, or processing past experiences.
The original YSEX? contains over 140 items and was developed as a comprehensive research taxonomy of sexual motivation. The YSEX-SF was created by the same authors, who selected or wrote the two most representative items for each motivational domain, reducing completion time substantially while retaining the structure of the original. Scores on the short form correlate strongly with their long-form counterparts. The short form also introduced one new subscale, Reproduction, and renamed the Utilitarian subscale to Practical.
Yes. The instructions ask respondents who have not had sex to rate how likely each reason would be to lead them to have sex. Their profile reflects anticipated rather than experienced motivation, which can still be clinically useful, for example in work with clients who are anxious about sexual relationships or exploring their readiness for them.
Not necessarily. The pattern across subscales is often more informative than any single score. Most people report a combination of motivations rather than a single dominant reason, and results are best interpreted alongside the client’s history, presenting concerns, and broader clinical assessment.
Meston, C. M., Kilimnik, C. D., Freihart, B. K., & Buss, D. M. (2020). Why humans have sex: Development and psychometric assessment of a short-form version of the YSEX? instrument. Journal of Sex & Marital Therapy, 46(2), 141–159. https://doi.org/10.1080/0092623X.2019.1654581
Developed at the Meston Lab, The University of Texas at Austin. The original 142-item Why Have Sex? Questionnaire (YSEX?) was developed by Meston and Buss (2007). Included on NovoPsych with the authors’ permission.
Meston, C. M., & Buss, D. M. (2007). Why humans have sex. Archives of Sexual Behavior, 36(4), 477–507. https://doi.org/10.1007/s10508-007-9175-2
Meston, C. M., Kilimnik, C. D., Freihart, B. K., & Buss, D. M. (2020). Why humans have sex: Development and psychometric assessment of a short-form version of the YSEX? instrument. Journal of Sex & Marital Therapy, 46(2), 141–159. https://doi.org/10.1080/0092623X.2019.1654581
