The Desire Index Methodology

Why This Document Exists

Most assessments about sex and relationships are not really assessments. They are quizzes — collections of questions written by content marketers, scored by arbitrary point systems, and designed to produce a result the user wanted to hear before they began. They have the aesthetics of science without any of the substance.

Desire Index is different, and this document exists to prove it. Every domain in the assessment maps to peer-reviewed research. Every interpretation offered is grounded in findings from named researchers whose work has shaped how the field understands desire. This document explains how the index is built, what it measures, why we measure those things specifically, and what the resulting scores actually mean. It is written so that a clinician, a researcher, or a curious user can verify the work for themselves.

The Core Insight

Sexual desire in long-term relationships does not fade randomly. It does not fade because love has died. It does not fade because of a single deficiency. It fades because specific, identifiable conditions stop being met — biological, psychological, and relational conditions that the research literature has documented across decades of empirical work.

The clinical question, then, is not “is your desire low?” That question is too coarse to be useful. The useful question is: “Which specific conditions for desire are intact in your relationship, and which have eroded?” Once you know that, the path forward becomes clear.

This is what Desire Index measures. It identifies, across seven research-backed domains, which conditions are sustaining desire and which are suppressing it. It then uses that pattern to give the user a specific picture of what is actually happening in their relationship — not a generic score, but a diagnosis.

The Seven Domains

The assessment measures desire through seven domains. Each was selected because it represents a distinct mechanism the research literature identifies as causally relevant to sexual desire in long-term relationships.

1. Attachment & Vulnerability

The attachment system and the sexual system are intertwined. When the attachment system is activated through emotional vulnerability, felt safety, or partner responsiveness, it can potentiate the sexual system. When the attachment system is threatened through conflict, perceived rejection, or emotional withdrawal, it suppresses sexual desire and redirects energy toward self-protection.

The foundational framework for understanding adult attachment in romantic relationships was established by Hazan and Shaver, who proposed that romantic love operates as a biosocial process structurally similar to infant-caregiver attachment (Hazan & Shaver, 1987). Mario Mikulincer and Phillip Shaver synthesized two decades of empirical work in their reference text Attachment in Adulthood (Mikulincer & Shaver, 2016).

Birnbaum and colleagues found that attachment anxiety was associated with an ambivalent construal of sexual experience, while attachment avoidance was associated with more aversive sexual feelings, more emotional detachment during sex, and inhibition of the positive relational effects of sex (Birnbaum et al., 2006). A subsequent study found that perceiving one’s partner as responsive heightened sexual desire for that partner (Birnbaum et al., 2016).

The domain measures eight dimensions of attachment-relevant behavior: whether the person turns toward their partner first when distressed, whether they can show their partner the parts of themselves they are ashamed of, whether their partner’s vulnerability draws them closer, whether they feel actively wanted (not just loved), whether they can stay present during conflict, whether they have shared the deep architecture of their childhood, whether they instinctively move toward a partner who is falling apart, and whether they trust their vulnerabilities will not be weaponized.

2. Closeness vs. Otherness

Desire requires a psychological gap to arc across. Closeness and desire have a complex, non-linear relationship — closeness is generally beneficial for desire, but the specific dimension of otherness(the degree to which one’s partner is perceived as a separate, autonomous, not-fully-known person) appears to do distinct work. Recent reviews have proposed that high closeness is most strongly linked to desire when paired with the maintenance of otherness (Muise & Goss, 2024).

Prekatsounaki and colleagues developed measures of “celebrated otherness” and found that it correlated with higher sexual desire in women in long-term relationships. The same study introduced “object-of-desire affirmation” as the strongest single predictor of women’s sexual desire (Prekatsounaki et al., 2019). Sims and Meana identified over-familiarity and de-sexualization of roles as core themes in women’s own attributions for declining desire (Sims & Meana, 2010). Ferreira and colleagues found that autonomy and partner separateness were dominant themes in what helps maintain desire (Ferreira et al., 2015).

The domain measures eight dimensions of otherness: whether the person can recall feeling a spark while watching their partner absorbed in something they love, whether the partner has a world of their own, whether absence activates longing, whether the partner can still surprise them, whether the person actively cultivates their own identity, and whether they have friendships and social life of their own.

3. Biology & Inhibition

Desire has both a biological floor and an inhibition ceiling. The biological floor refers to the body’s hormonal, energetic, and neurochemical infrastructure. The inhibition ceiling refers to the psychological brakes that can suppress desire even when the biological floor is intact — spectatoring, sexual shame, body image interference, and performance anxiety.

French and colleagues found that individual differences in circulating testosterone explained the observed sex difference in spousal desire, while relational, cognitive, and emotional variables did not (French et al., 2022). Gettler and colleagues found that men who became fathers experienced large declines in testosterone, with the largest drops in men most involved in caregiving (Gettler et al., 2011). McNulty and colleagues documented that women’s sexual desire declined more steeply over time than men’s and that childbirth partially accounted for this decline (McNulty et al., 2019).

On the inhibition side, the conceptual framework of sexual response as the net result of competing accelerator and brake systems has been developed in the research literature and popularized by Emily Nagoski in Come As You Are (Nagoski, 2015).

The domain measures ten dimensions: six on the accelerator side (sleep, exercise, stress capacity, spontaneous arousal, substance reliance, physical vitality) and four on the brake side (presence during sex, freedom from sexual shame, body image during intimacy, freedom from performance anxiety).

4. Imagination & Erotic Space

Desire often lives in the imagination before it lives in the body. Rosemary Basson formalized this in her circular model of female sexual response — for many people, especially women in long-term relationships, the sequence is not desire → arousal → sex but rather emotional intimacy → willingness → arousal → desire (Basson, 2000). Esther Perel has articulated how the mental space for fantasy, anticipation, and playfulness gets colonized by logistics and routine (Perel, 2006).

This domain measures the person’s own internal erotic state, not how they feel about their partner’s behavior toward them. The eight dimensions: whether the partner occupies the person’s erotic imagination, whether their sex life has variety, whether desire feels permitted rather than fraught, whether anticipation still has a charge, whether erotic energy flows toward the partner, whether flirtation exists outside the bedroom, and whether the person can recall a recent moment of visceral physical attraction.

5. Mutual Responsiveness

Responsiveness operates in two directions: how the person responds to their partner’s bids for connection, and whether the person feels actively wanted by their partner. Birnbaum and colleagues found that perceiving one’s partner as responsive predicts heightened sexual desire (Birnbaum et al., 2016).

The “felt desire” sub-construct is critical. Prekatsounaki and colleagues called this “object-of-desire affirmation” and found it was the single strongest predictor of sexual desire among the constructs they measured (Prekatsounaki et al., 2019).

The domain measures twelve dimensions: warm rejection patterns, attentiveness to partner’s preferences, ability to talk about sex directly, the post-sex emotional landscape, partner curiosity, ability to receive expressed desire, attunement to small bids, mutual investment during sex, daily non-sexual touch, presence in shared physical space, and the two felt-desire dimensions: whether the person feels sexually attractive to their partner and whether they feel pursued rather than merely tolerated.

6. Role Dynamics & Power

When couples fall into rigid roles — particularly a parent-child dynamic where one partner manages and the other complies or resists — the erotic charge between them can dissipate. The transition to parenthood is the single largest documented compression event for sexual desire in the research literature (McNulty et al., 2019; Gettler et al., 2011).

The domain measures seven dimensions: whether the couple operates as genuine equals, whether the person can still see their partner as a lover, whether the distribution of responsibilities feels fair, whether the person takes initiative without being asked, whether the couple has protected their identity as a couple, whether they treat their partner with genuine respect, and whether they still go on real dates with intention and effort.

7. Identity & Aliveness

Desire requires a self that feels like something. If a person feels depleted, stuck, or reduced to their functional roles, they may not generate desire because desire is an expression of aliveness.

Two constructs are particularly relevant. The first is sexual self-concept— distinct from general self-concept. A person can feel generally confident while simultaneously feeling sexually undesirable. This gap was a central theme in Sims and Meana’s qualitative interviews (Sims & Meana, 2010). The second is the role of growth, novelty, and shared exploration in maintaining desire over time.

The domain measures ten dimensions: whether the person feels they are becoming something, whether they feel attractive and vital, whether their work energizes them, whether they have an embodied relationship with their body, whether they bring new things back to the relationship, whether they can access play, whether they invest in how they show up for their partner, whether they handle their own emotional regulation, whether they feel desirable as a sexual being, and whether laughter is still alive between the partners.

The Cross-Domain Architecture

The seven domains do not operate independently. The index’s analytical value comes not from individual scores but from how they interact.

Biology constrains everything above it.A person with critically low Biology & Inhibition scores will not benefit from relational interventions until the biological floor is raised.

Attachment is the foundation.If Attachment & Vulnerability is critically low, the person does not feel safe enough for the other domains to function.

Otherness and Imagination are tightly coupled. Low Otherness almost always produces low Imagination. When there is no psychological space between partners, there is little for the erotic imagination to work with.

Imagination and Responsiveness form a four-quadrant framework:

• High Imagination + High Responsiveness = the erotic system is healthy. The person wants and feels wanted.
• High Imagination + Low Responsiveness = the person’s erotic mind is alive but they don’t feel their partner meeting it. Loneliness within desire.
• Low Imagination + High Responsiveness = the partner is present but the person’s own erotic engine has stalled. The issue is internal.
• Low Imagination + Low Responsiveness = both the internal spark and the external signal have faded. The “parallel lives” pattern.

Roles and Responsiveness interact through resentment. Chronic role imbalance generates resentment, which suppresses responsiveness. Improving Role Dynamics often unlocks Responsiveness without direct intervention.

Identity feeds Otherness. A person with strong Identity naturally generates Otherness because they bring something distinct to the relationship.

The parenthood compression is the most important multi-domain pattern. The transition to parenthood simultaneously hits Biology (sleep deprivation, hormonal shifts including documented testosterone decline in fathers), Roles (massive increase in domestic labor), Identity (role reduction and de-eroticization of self-concept), and Otherness (constant togetherness). The combined findings from Gettler (2011) and McNulty et al. (2019) describe complementary halves of the same compression event.

The Question Architecture

The assessment contains 63 questions distributed across the seven domains. Each question was written to measure a specific behavioral, cognitive, or affective construct identified in the research as causally relevant to desire.

• Attachment & Vulnerability: 8 questions
• Closeness vs. Otherness: 8 questions
• Biology & Inhibition: 10 questions
• Imagination & Erotic Space: 8 questions
• Mutual Responsiveness: 12 questions
• Role Dynamics & Power: 7 questions
• Identity & Aliveness: 10 questions

Each question is scored on a 7-point Likert scale anchored by specific descriptive language at each pole, not numbers alone. This anchoring approach reduces the response distortion common in quizzes that ask users to rate themselves on abstract scales.

Domain scores are calculated as the mean of all answered questions in that domain. There is no weighting, no inverse scoring, no derived composite metric. The simplicity is deliberate — the analytical value comes from the pattern across domains, not from any single statistical operation on the data.

How the Analysis Works

After the assessment is complete, the user’s domain scores are interpreted against a structured knowledge base containing the research literature, cross-domain interaction rules, common common profiles, and worked examples of high-quality analysis.

The analysis is built around three components. The first establishes how the analyst communicates: leading with the user’s strongest domain, calibrating language severity precisely to score range, identifying the meaningful signal across two or three domains, naming the cross-domain interactions, and closing with a question that invites further exploration.

The second is the knowledge base itself — a synthesis of the research literature on each domain, the cross-domain interactions, common common profiles, and gender differences in desire. It contains specific findings from named researchers, theoretical frameworks, and the named patterns the analyst is trained to recognize.

The third is a set of worked examples — moderate solo, severe solo, couple comparison, and broadly healthy solo — that demonstrate the quality, structure, and tone the analysis is calibrated to produce.

Interpretations are not generated from scratch. They are pattern-matched against the research-grounded knowledge base. Every claim is traceable to a finding in the literature.

What the Index Is Not

It is not therapy. Desire Index does not provide treatment, diagnosis of clinical conditions, or ongoing therapeutic support. Users in genuine distress are directed to licensed mental health professionals.

It is not a clinical instrument. The 63-question assessment has not been formally validated through psychometric testing in the way that established instruments like the Female Sexual Function Index have been. It is a research-grounded index, not a validated clinical scale. We are open about this distinction.

It is not a substitute for couples therapy when serious problems exist. If the index reveals patterns suggesting attachment trauma, abuse, or compounding distress, the right response is professional support.

It is not a quiz designed to make you feel good. The assessment is honest about what the research finds, including when those findings are uncomfortable.

It is not a tool that will fix your relationship. It is a tool that will help you understand what is happening with greater precision than you had before. What you do with that understanding is up to you.

What the Index Is

It is a research-grounded, personalized, and accessible tool for understanding desire in long-term relationships. It draws from the work of researchers and clinicians whose findings shape contemporary understanding of attachment, sexual response, partner responsiveness, and the biology of pair-bonding.

It is free at the entry point because the index itself should not be gated behind a paywall. The free version provides the full 63-question assessment, scored domains, and a personalized analysis. Paid tiers offer interactive consultation, partner comparison with interaction-effect detection, and live mediated sessions.

It is designed to be honest. The analyst will tell you that your strengths are real strengths. It will also tell you, when the data warrants, that your relationship has patterns the research identifies as concerning — and what the literature suggests about what helps.

A Note on Vulnerability

The questions in this assessment are personal. Some are about your body, your shame, your fears, your fantasies, the things you have not told anyone. We know this. We have designed the product around the assumption that you will only answer honestly if you trust that your individual answers will remain private — visible to no one, including your partner.

That trust is enforced architecturally. Your individual answers are encrypted at rest. They are never sent to your partner’s device, even in the comparison view. The analyst receives only your domain-level scores, not your individual responses, and is explicitly instructed to never reference specific answers.

If you are worried about answering honestly, here is what we want you to know: the questions that feel most exposing are usually the ones that contain the most analytical information. The more honestly you answer, the more useful the result will be. And the more honest you are with yourself in this private space, the more equipped you become to be honest with the people in your life who matter.

That is, ultimately, what this is for.

References

Each citation below has been verified. DOI links lead directly to the published article.

• Basson, R. (2000). The female sexual response: A different model. Journal of Sex & Marital Therapy, 26(1), 51–65. doi:10.1080/009262300278641
• Birnbaum, G. E., Reis, H. T., Mikulincer, M., Gillath, O., & Orpaz, A. (2006). When sex is more than just sex. Journal of Personality and Social Psychology, 91(5), 929–943. doi:10.1037/0022-3514.91.5.929
• Birnbaum, G. E., et al. (2016). Intimately connected: The importance of partner responsiveness for experiencing sexual desire. Journal of Personality and Social Psychology, 111(4), 530–546. doi:10.1037/pspi0000069
• Ferreira, L. C., Fraenkel, P., Narciso, I., & Novo, R. (2015). Is committed desire intentional? Family Process, 54(2), 308–326. doi:10.1111/famp.12108
• French, J. E., McNulty, J. K., et al. (2022). An empirical investigation of the roles of biological, relational, cognitive, and emotional factors in explaining sex differences in dyadic sexual desire. Biological Psychology, 174, 108421. doi:10.1016/j.biopsycho.2022.108421
• Gettler, L. T., McDade, T. W., Feranil, A. B., & Kuzawa, C. W. (2011). Longitudinal evidence that fatherhood decreases testosterone in human males. Proceedings of the National Academy of Sciences, 108(39), 16194–16199. doi:10.1073/pnas.1105403108
• Hazan, C., & Shaver, P. (1987). Romantic love conceptualized as an attachment process. Journal of Personality and Social Psychology, 52(3), 511–524. doi:10.1037/0022-3514.52.3.511
• McNulty, J. K., Maxwell, J. A., Meltzer, A. L., & Baumeister, R. F. (2019). Sex-differentiated changes in sexual desire predict marital dissatisfaction. Archives of Sexual Behavior, 48(8), 2473–2489. doi:10.1007/s10508-019-01471-6
• Mikulincer, M., & Shaver, P. R. (2016). Attachment in adulthood (2nd ed.). Guilford Press.
• Muise, A., & Goss, S. (2024). Does too much closeness dampen desire? Current Directions in Psychological Science, 33(1), 41–47. doi:10.1177/09637214231211542
• Nagoski, E. (2015). Come as you are. Simon & Schuster.
• Perel, E. (2006). Mating in captivity. HarperCollins.
• Prekatsounaki, S., Janssen, E., & Enzlin, P. (2019). In search of desire. Journal of Sex & Marital Therapy, 45(5), 414–423. doi:10.1080/0092623X.2018.1549633
• Sims, K. E., & Meana, M. (2010). Why did passion wane? Journal of Sex and Marital Therapy, 36(4), 360–380. doi:10.1080/0092623X.2010.498727

This list is not exhaustive. Additional foundational works — including research on the dual control model (Janssen and Bancroft), bid-response patterns (Gottman), self-expansion theory (Aron), sexual communal strength (Muise, Impett), and the transition to parenthood (Doss, Rosen) — inform the knowledge base and will be added as additional citation verification is completed. Researchers interested in the complete bibliography may contact us at hello@desireindex.ai.

Authors

Desire Index was created by Jonathan Hiller. Jonathan is a documentary filmmaker (Netflix, National Geographic, CNN) and former Director of Content for a U.S. presidential campaign. His undergraduate honors thesis at The College of Wooster examined mindfulness and frontal lobe function, building on research conducted at the Davidson Lab at the University of Wisconsin-Madison.

The Desire Index exists because the research on desire in long-term relationships is remarkably precise — and remarkably inaccessible. The science is locked in academic papers and clinical textbooks. The popular advice is vague at best. This tool bridges that gap.

We are not affiliated with, endorsed by, or formally connected to any of the researchers cited. Their work is referenced because it forms the empirical foundation for this tool. Any errors of interpretation are ours alone.