It's Not You, It's Me: Using Self-Determination Theory to Explore Personal Contributions to Relationship Quality Through Relationship Motivation and Behaviours

Abstract

Given that lack of support is an often-cited reason for separation and divorce (e.g., Joel et al., 2018), knowing how one's own specific interpersonal behaviours contribute to supporting one's partner may inform avenues to promote relationship satisfaction. Relationship science has mostly focused on broader perceptions of receiving support in romantic relationships without considering how one's own specific behaviours are associated with their relationship satisfaction or may be affected by one's motivation to be in the relationship. Self-determination theory researchers have identified specific behaviours that support or thwart a person's psychological needs. Need-supportive partners offer choice, provide valuable feedback, and communicate interest to their partners, whereas need-thwarting partners limit choice, question their partner's abilities, and do not express care to their partners (Rocchi et al., 2017). Using cross-sectional and prospective methods across two different samples of partnered individuals, I explored whether supporting or thwarting one's partner's psychological needs interacted with one's relationship motivation and was associated with one's own relationship satisfaction. Following this, using dyadic data from community couples, I examined the interdependent associations between supporting and thwarting behaviours and relationship and sexual satisfaction for both partners.

Study 1 enlisted cross-sectional data from partnered individuals to examine how one's own need-supportive and need-thwarting behaviours (e.g., supporting partners' decisions and skill development vs. questioning their decisions and worth) moderated associations between one's relationship motivation and their relationship satisfaction. Autonomous relationship motivation was most positively associated with relationship satisfaction at lower levels of need-supportive behaviours and higher levels of need-thwarting behaviours. Controlled relationship motivation was most negatively associated with relationship satisfaction at lower levels of need-supportive behaviours and higher levels of need-thwarting behaviours. All pathways were significant for analyses in which participants identified as female except for need-thwarting behaviours moderating the association between controlled motivation and lower relationship satisfaction (which was the only significant pathway for males).

Study 2 assessed whether one's own need-supportive and need-thwarting behaviours mediated the relationship between self-determined motivation for specific relational activities (e.g., niceties, intimacy) and relationship satisfaction reported three months later. When partnered participants reported supporting their partners' basic psychological needs, their need-supportive behaviours mediated the association between their autonomous motivation and their higher relationship satisfaction. Engaging in fewer need-supportive behaviours mediated the association between participants' controlled motivation and lower relationship satisfaction. When partnered participants reported thwarting their partners' basic psychological needs, their need-thwarting behaviours mediated the association between their controlled motivation and their lower relationship satisfaction. Engaging in fewer need-thwarting behaviours mediated the association between participants' autonomous motivation and their higher relationship satisfaction. Mediation findings related to need-supportive behaviours remained significant when controlling for baseline satisfaction.

Finally, Study 3 examined the dyadic associations between one's own need-supportive and need-thwarting behaviours and one's own and one's partner's relationship and sexual satisfaction. When participants engaged in need-supportive behaviours towards their partner, they and their partner reported higher relationship satisfaction. When participants engaged in need-thwarting behaviours towards their partner, they and their partner reported lower relationship satisfaction. One's own need-supportive and need-thwarting behaviours were positively and negatively associated with their sexual satisfaction, respectively, but not with the sexual satisfaction of their partner. Most actor effects remained significant when controlling for perceptions of partners' behaviours. However, only one's perceptions of their partner's need-thwarting behaviours were associated with their lower sexual satisfaction.

My findings shift self-determination theory's focus from receipt to provision of support for all three basic psychological needs, while also stressing the importance of considering correlates of lower relationship and sexual satisfaction, like need-thwarting behaviours and controlled motivation. My results validate the use of clinical approaches that examine both partners’ need-supportive and need-thwarting behaviours and the motivational context in which behaviours occur.