Sexual Desire Inventory

Sexual Desire Inventory

ILANA P. SPECTOR,1 SMBD Jewish General Hospital

MICHAEL P. CAREY, Syracuse University

LYNNE STEINBERG, Oklahoma State University

The Sexual Desire Inventory (SDI) is a self-administered questionnaire developed to measure sexual desire. To date, sexologists have had difficulty measuring this construct. Previous measurement of sexual desire involved either indirect measurement through examining frequency of sexual behavior, or by broad self-report of cognitions such as “rate your level of sexual desire.” Both these methods are less accurate measures of sexual desire because first, sexual

desire is theoretically a multidimensional construct, and second, no empirical data are available to suggest that sexual desire and behavior are perfectly correlated. For the purposes of this questionnaire, sexual desire was defined as interest in sexual activity, and it was measured as primarily a cognitive variable through amount and strength of thought directed toward approaching or being receptive to sexual stimuli.

Description

The items of the SDI were selected by considering theoretical models of desire and clinical experience in assessing sexual desire disorders. They were presented initially to sexologists and then to a small pilot sample (N = 20 students) who rated the clarity and content validity of the items. Next, a sample of 300 students completed the SDI. Based on factor analytic data, items were eliminated or reworded to measure two dimensions of sexual desire: dyadic sexual desire (interest in behaving sexually with a partner) and solitary sexual desire (interest in behaving sexually by oneself).

To date, the 11-item SDI has been administered to three samples for the purpose of collecting psychometric data. These samples include 380 students (Spector, Carey, & Steinberg, 1996), 40 subjects living in geriatric long-term care facilities (Spector & Fremeth, 1996), and 40 couples (Spector & Davies, 1995). The SDI can be used to measure sexual desire in both the general population or in clinical samples. It has been used to measure sexual desire with both younger (M age = 20.8) and older (M age = 82.5) samples, and individuals and couples.

Response Mode and Timing

For each item, respondents are asked to circle the number that best reflects their thoughts and feelings about their interest in or wish for sexual activity. They are asked to use the last month as a referent. For the three frequency items (Items 1, 2, 10), respondents circle one of seven options. For the remain- ing eight strength items, respondents rate their level of sexual desire on an 8-point Likert-type scale. Most respondents complete the scale within 5 minutes.

Scoring

Items 1–8 are summed to obtain a Dyadic Sexual Desire score. Items 9–11 are summed to obtain a Solitary Sexual Desire score. Within a couple, female dyadic scores can be subtracted from male dyadic scores to obtain a desire discrepancy score.

Reliability

Internal consistency estimates (using Cronbach’s alpha coefficients) were calculated for the Dyadic scale (r = .86) and the Solitary scale (r = .96), indicating strong evidence of reliability (Spector et al., 1996). Test-retest reliability was calculated at r = .76 over a 1-month period (Carey, 1995).

Validity

Evidence for factor validity has been examined. Factor analyses revealed that Items 1–8 loaded high (i.e., >.45) on the

dyadic factor, whereas Items 9–11 loaded high on the solitary factor. Both factors had eigenvalues > 1 (Spector et al., 1996).

Concurrent validity evidence, collected from 380 students, revealed that solitary sexual desire is correlated with the frequency of solitary sexual behavior (r = .80, p <.0001), and with erotophilia (r = –.28, p < .0001; Spector, 1992). Dyadic desire is correlated with the frequency of dyadic sex- ual behavior (r = .34, p < .0001). Note that neither dyadic nor solitary desire is perfectly correlated with sexual behavior, indicating that measuring desire indirectly through behavior would be inaccurate. Discriminant validity evidence reveals that neither subscale of the SDI is correlated with social desirability (Spector, 1992).

A second study conducted on 40 couples revealed that, for females, dyadic desire is positively correlated with relation- ship adjustment as measured by the Dyadic Adjustment Scale (Spanier, 1976; r = .54, p < .001), with sexual satisfaction as measured by the Index of Sexual Satisfaction (Hudson, Harrison, & Crosscup, 1981; r = .63, p <.001), with sexual daydreams as measured by the Sexual Daydreams Scale (Giambra, 1980; r = .53, p < .001), and with sexual arousal as measured by the Sexual Arousal Inventory (Hoon, Hoon, & Wincze, 1976; r = .71, p < .001). With males, dyadic sexual desire is only correlated with sexual satisfaction (r = .36, p < .01; Spector & Davies, 1995).

Gender differences have been noted on the SDI. Males have significantly higher levels of dyadic, F(1, 374) = 5.79, p < .05, and solitary, F(1, 376) = 55.15, p < .0001, desire than do females. This difference is also found in geriatric samples (Spector & Fremeth, 1996).

Sexual Desire Inventory

This questionnaire asks about your level of sexual desire. By desire, we mean interest in or wish for sexual activity. For each item, please circle the number that best shows your thoughts and feelings. Your answers will be private and anonymous.

1. During the last month, how often would you have liked to engage in sexual activity with a partner (for example, touching each other’s genitals, giving or receiving oral stimulation, intercourse, etc.)?

   1. Not at all 4) Twice a week

   2. Once a month 5) 3 to 4 times a week

   3. Once every two weeks 6) Once a day

   4. Once a week 7) More than once a day

2. During the last month, how often have you had sexual thoughts involving a partner?

   1. Not at all 4) 3 to 4 times a week

   2. Once or twice a month 5) Once a day

   3. Once a week 6) A couple of times a day

   4. Twice a week 7) Many times a day

3. When you have sexual thoughts, how strong is your desire to engage in sexual behavior with a partner?

   0 1 2 3 4 5 6 7 8

   No desire Strong desire

4. When you first see an attractive person, how strong is your sexual desire?

   0 1 2 3 4 5 6 7 8

   No desire Strong desire

5. When you spend time with an attractive person (for example, at work or school), how strong is your sexual desire? 0 1 2 3 4 5 6 7 8

   No desire Strong desire

6. When you are in romantic situations (such as a candle-lit dinner, a walk on the beach, etc.), how strong is your sexual desire? 0 1 2 3 4 5 6 7 8

   No desire Strong desire

7. How strong is your desire to engage in sexual activity with a partner?

   0 1 2 3 4 5 6 7 8

   No desire Strong desire

8. How important is it for you to fulfill your sexual desire through activity with a partner?

   0 1 2 3 4 5 6 7 8

   Not at all Extremely

   important important

9. Compared to other people of your age and sex, how would you rate your desire to behave sexually with a partner? 0 1 2 3 4 5 6 7 8

   Much less Much more

   desire desire

10. During the last month, how often would you have liked to behave sexually by yourself (for example, masturbating, touching your genitals etc.)?

    1. Not at all 4) Twice a week

    2. Once a month 5) 3 to 4 times a week

    3. Once every two weeks 6) Once a day

    4. Once a week 7) More than once a day

11. How strong is your desire to engage in sexual behavior by yourself?

    0 1 2 3 4 5 6 7 8

    No desire Strong desire

12. How important is it for you to fulfill your desires to behave sexually by yourself?

    0 1 2 3 4 5 6 7 8

    Not at all Extremely

    important important

13. Compared to other people of your age and sex, how would you rate your desire to behave sexually by yourself? 0 1 2 3 4 5 6 7 8‌

    Much less Much more

    desire desire

14. How long could you go comfortably without having sexual activity of some kind?

    1. Forever 5) A week

    2. A year or two 6) A few days

    3. Several months 7) One day

    4. A month 8) Less than one day

    5. A few weeks

Address correspondence to Ilana P. Spector, Behavioral Psychotherapy and Research Unit, Department of Psychiatry, SMBD Jewish General Hospital, 4333 Cote St. Catherine Road, Montreal, Quebec, Canada, H3T 1E4; e-mail: [email protected]

References