The Spanish version of the Sexual Inhibition/Sexual Excitation Scales-Short Form: Establishing measurement invariance across sexual orientation.

The Dual Control Model (DCM) conceptualizes sexual response as the result of integrating two neurophysiological systems (excitatory and inhibitory), where psychological, physiological, and behavioral factors are involved. Regarding DCM-derived measures, few studies have included sexual minority participants. Therefore, the present study aimed to provide additional validity evidence in bisexual and gay populations of the Sexual Inhibition/Sexual Excitation Scales-Short Form (SIS/SES-SF), a widely used scale derived from the DCM. The measurement invariance by sexual orientation of the SIS/SES-SF was analyzed, its scores were compared, and its relationship with sexual functioning was examined. 9,290 men and women were assessed between January 2022 and June 2023. They were classified into bisexual, gay, and heterosexual individuals. Results showed strict measurement invariance of SIS/SES-SF by sexual orientation in women, and weak/metric measurement invariance in men. Bisexual and gay men reported more propensity for sexual excitation and sexual inhibition than heterosexual men, although these differences should be cautiously taken since the scale does not reach the maximum level of invariance. Furthermore, bisexual women indicated more propensity for sexual excitation and less sexual inhibition due to sexual consequences than heterosexual and lesbian women. Heterosexual women reported the highest sexual inhibition due to sexual performance failure. Scores on the SIS/SES-SF subscales were significantly related to sexual functioning, especially sexual arousal and lubrication/erection. This study provides researchers and clinicians with an assessment instrument that provides reliable and valid measures to examine the propensity for sexual excitation/inhibition of bisexual and gay people; moreover, in the case of women, it allows comparison of bisexuals, heterosexuals, and lesbians.