Although evidence suggests that both men and women perpetrate sexual coercion, the majority of work has traditionally focused on men as perpetrators and women as victims. Psy-chological factors, including psychopathic traits and sexual motivations, have been proposed to characterize sexually coercive men. However, the sparse existing research using female samples suggests that these models may not adequately characterize female sexual coercers. In particular, although there is evidence that sexual motivations may mediate the relationship between psycho-pathic traits and coercion perpetration, there is a dearth of information regarding gender as a po-tential moderator of these mediating paths. To improve our understanding of these relationships, the current study examines a moderated mediation model in which sexual motivations mediate the relationship between psychopathic traits and sexual coercion, with gender as a potential mod-erator of these mediation effects. To achieve this goal, 868 undergraduate participants were re-cruited to take part in an online survey. Study aims were accomplished using a combination of regression and path analysis. Results implicated Factor 2 traits as particularly important to male-perpetrated but not female-perpetrated coercion, and that this relationship was partially mediated by sexual power motives. In sum, our results support a conceptual model of male perpetration where men who are high in Factor 2 traits (impulsivity and behavioral dyscontrol) may engage in sexual coercion in an attempt to feel powerful. These results and their implications are discussed in the context of men and women’s changing social roles, and how individual psychopathology may dovetail with social beliefs to generate sexually coercive behavior.

People engage in sex for a wide variety of reasons and these reasons can differ depending on the individual, his or her partner, and on the context of the sexual encounter. The purpose of this dissertation was to examine how sexual attraction and sexual orientation, of both self and partner, affect an individual’s reasons to engage in sex, or sexual motivation. Three studies were conducted to explore these effects from both the individual’s and the partner’s perspective. In Study 1, individual attitudes toward having casual sex, dating, and being in a committed relationship with a bisexual partner of the other gender were examined in a sample of 720 men and women. Participants reported negative attitudes toward having these relationships and more negative attitudes were reported as the commitment level of the considered relationship increased. Women also reported more negative attitudes and greater insecurity toward relationships than men. In Study 2, the psychometric properties of a comprehensive research tool, the Why Have Sex? (YSEX?) questionnaire to use in Study 3 for the study of sexual motivation were evaluated in a sample of 146 women with same-sex attraction. Overall, the reliability of this scale was excellent for casual sex motivations and motivations for sex in committed relationships with female partners. In Study 3, motivations for sex and the effects of relationship context, sexual attraction, and the gender of one’s partner were explored in a sample of 510 women including women with same-sex attraction and women with exclusively heterosexual attraction. Results of this study showed that relationship context had the largest effect on sexual motivation; physical motivations were more strongly endorsed for casual sex while emotional motivations were more strongly endorsed for sex in committed relationships. No effect of sexual attraction was reported. Further, no effect of gender of partner was reported by sexual minority women. The results of this dissertation have important implications for the study of sexual motivation, specifically as it relates to sexual attraction and orientation. Motivations for sex are likely to be affected by an individual’s attitudes and perceptions of his or her partner’s sexual orientation and associated stereotypes. In addition, the type of sexual relationship and associated level of commitment had strong, differential effects on sexual motivation. This is a novel finding as the context of the sexual relationship has not previously been considered with respect to individual motivations for sex. Henceforth, studies on sexual motivation need to be more contextualized and include more comprehensive assessments of individuals to increase the validity of findings and demonstrate the complex variation of human sexual motivation.

A growing number of studies suggest that the reasons for which people engage in sexual activities matter for their sexual well-being. Grounded in self-determination theory (SDT), this thesis research investigated the contributions of autonomous and controlled sexual motivation to sexual well-being. These objectives were achieved through a series of five studies presented in four manuscripts. In Manuscript 1, we validated the Sexual Motivation Scale (SexMS), a measure of self-regulation for sexual activities grounded in SDT (Study 1: N = 1,070, Study 2: N = 575). Collectively, the findings provided strong support for the factorial validity of the SexMS. Additionally, the SexMS captured important individual differences in sexual well-being, specifically with respect to sexual satisfaction, sexual distress, and sexual function. Manuscript 2 explored how autonomous and controlled sexual motivation are integrated with broader psychological functioning by examining their motivational antecedents and well-being consequences (N = 828). The results showed that global and relational motivation explained individual differences in autonomous and controlled sexual motivation. Additionally, autonomous and controlled sexual motivation explained individual differences in sexual, relational, and global well-being. Finally, the results suggested that, for the most part, the associations between the motivational antecedents and the well-being consequences of autonomous and controlled sexual motivation followed a heterarchical structure. Next, in Manuscript 3, the motivational sequence proposed by SDT – in which basic psychological needs satisfaction predicts quality of motivation, and in turn quality of psychological functioning – was validated in the context of within-person variations in sexual well-being (N = 113). The results indicated that on days when people experience more basic psychological needs satisfaction during interactions with their partner, their sexual motivation was more autonomous and this was associated with higher sexual well-being. However, basic needs satisfaction did not significantly predict controlled sexual motivation. Additionally, on days when people reported higher controlled sexual motivation, they experienced lower sexual well-being. Finally, in Manuscript 4, we examined the motivational sequence proposed by SDT from a dyadic perspective to better understand the contribution of sexual motivation to sexual well-being in couples (N = 225 couples). Specifically, we examined whether basic needs satisfaction during sexual activities and autonomous and controlled sexual motivation in one partner influenced the sexual well-being of the other partner. The unique contribution of each basic psychological need (i.e., autonomy, competence, and relatedness) to sexual well-being was also investigated. Taken together, the results supported SDT’s predictions regarding the relevance of the motivational sequence and the unique contribution of each basic psychological need in explaining between-couple differences in sexual well-being. However, different patterns of association emerged for women and men, suggesting that in the context of sexual activities within heterosexual relationships, the motivational processes proposed by SDT may be moderated by gender. In sum, the findings from this thesis extend SDT and sexual motivation research. Overall, SDT may provide novel insights on human sexual behaviour, notably by improving our understanding of the factors that can enhance or impede sexual well-being in committed relationships.

People engage in sex for a wide variety of reasons and these reasons can differ depending on the individual, his or her partner, and on the context of the sexual encounter. The purpose of this dissertation was to examine how sexual attraction and sexual orientation, of both self and partner, affect an individual’s reasons to engage in sex, or sexual motivation. Three studies were conducted to explore these effects from both the individual’s and the partner’s perspective. In Study 1, individual attitudes toward having casual sex, dating, and being in a committed relationship with a bisexual partner of the other gender were examined in a sample of 720 men and women. Participants reported negative attitudes toward having these relationships and more negative attitudes were reported as the commitment level of the considered relationship increased. Women also reported more negative attitudes and greater insecurity toward relationships than men. In Study 2, the psychometric properties of a comprehensive research tool, the Why Have Sex? (YSEX?) questionnaire to use in Study 3 for the study of sexual motivation were evaluated in a sample of 146 women with same-sex attraction. Overall, the reliability of this scale was excellent for casual sex motivations and motivations for sex in committed relationships with female partners. In Study 3, motivations for sex and the effects of relationship context, sexual attraction, and the gender of one’s partner were explored in a sample of 510 women including women with same-sex attraction and women with exclusively heterosexual attraction. Results of this study showed that relationship context had the largest effect on sexual motivation; physical motivations were more strongly endorsed for casual sex while emotional motivations were more strongly endorsed for sex in committed relationships. No effect of sexual attraction was reported. Further, no effect of gender of partner was reported by sexual minority women. The results of this dissertation have important implications for the study of sexual motivation, specifically as it relates to sexual attraction and orientation. Motivations for sex are likely to be affected by an individual’s attitudes and perceptions of his or her partner’s sexual orientation and associated stereotypes. In addition, the type of sexual relationship and associated level of commitment had strong, differential effects on sexual motivation. This is a novel finding as the context of the sexual relationship has not previously been considered with respect to individual motivations for sex. Henceforth, studies on sexual motivation need to be more contextualized and include more comprehensive assessments of individuals to increase the validity of findings and demonstrate the complex variation of human sexual motivation.

Love and sex change over the course of a relationship. The current research investigates the factors that contribute to sexual desire and sexual satisfaction in long-term couples. In two studies, the association between motivational goals for sex, interdependence, and sexual outcomes were explored. Study 1 was a cross-sectional survey. The results of Study 1 revealed that participants who engaged in sex more often for approach goals reported higher levels of desire, whereas participants who engaged in sex more often for avoidance goals reported lower levels of desire. Study 2 was a 21-day daily experience study involving a subset of the participants from Study 1. The results of Study 2 indicated that on days when participants reported engaging in sex more for approach goals they reported greater sexual desire, whereas on days when participants reported engaging in sex more for avoidance goals they reported lower levels of sexual desire. Partner-focused, as opposed to self-focused sexual goals, were primarily responsible for these associations. In both studies, relationship satisfaction was also associated with higher desire, and this was mediated by the tendency of people who are more satisfied to engage in sex more often for approach goals. In Study 2, approach goals moderated the impact of avoidance goals on sexual desire, and this association differed by gender. Stronger approach goals buffered against declines in sexual desire associated with avoidance goals for women, but not for men. The findings support the utility of applying a motivational framework to the study of sexuality in established couples and the greater relevance of partner-focused sexual goals in long-term relationships.