Research into the impact of companion animals on well-being has been both extensive and inconclusive, with studies finding both positive and negative relationships. The present research explored three previously unexamined relationship science concepts that may help clarify whether companion animals provide well-being benefits: self-expansion (the process of adding positive content to the self through incorporating new resources and perspectives into one’s identity or engaging in novel, exciting activities), perceived pet responsiveness, and perceived pet insensitivity; as well as attachment. We focused on dog and cat owners’ depression, anxiety, positive and negative affect, and loneliness through an online survey with a large sample population (N = 1359). We found that perceived pet insensitivity is a significant positive predictor of depression, anxiety, negative affect, and loneliness; that attachment is a significant positive predictor of depression, anxiety, and loneliness, and a significant negative predictor of positive affect; and that self-expansion is a significant positive predictor of positive affect, and a significant negative predictor of loneliness. Loneliness emerged as a mediator in the relationship between perceived pet insensitivity, attachment, self-expansion, and all mental well-being outcome variables. These findings indicate that perceived pet insensitivity, attachment, and self-expansion may play an important yet neglected role in well-being outcomes.

General and domain-specific (e.g., relationship-specific) mindfulness frequently predict salutary relationship outcomes. The present preregistered study examined whether general and relationship mindfulness predicted longitudinal change in positive and negative relationship quality via greater perceived partner responsiveness (PPR). One hundred couples completed a baseline lab session (Phase 1), a 14-day diary period (Phase 2), and a 2-month follow-up survey (Phase 3). Actor-Partner Interdependence Mediation Model analyses revealed that actors’ Phase 1 relationship mindfulness—but not general mindfulness—predicted increases in their own positive relationship quality from Phase 1–3 and decreases in their own negative relationship quality from Phase 1–3 indirectly via their own Phase 2 PPR. An exploratory alternate model testing if Phase 1 PPR predicted changes in Phase 1–3 relationship quality via Phase 2 relationship mindfulness did not reveal significant indirect effects. All results held when controlling for gender, age, and relationship length, and no partner effects emerged in any analysis. These findings further elucidate the relationship-enhancing role of mindfulness in couples and highlight PPR as a critical mediator explaining the link between domain-specific mindfulness and relationship quality. Implications for mindfulness-based training programs for couples are discussed.

Attachment anxiety and avoidance are generally associated with detrimental relationship processes, including more negative and fewer positive relationship behaviours. However, recent theoretical and empirical evidence has shown that positive factors can buffer insecure attachment. We hypothesised that relationship mindfulness (RM)—open or receptive attention to and awareness of what is taking place internally and externally in a current relationship—may promote better day-to-day behaviour for both anxious and avoidant individuals, as mindfulness improves awareness of automatic responses, emotion regulation, and empathy. In a dyadic daily experience study, we found that, while an individual’s own daily RM did not buffer the effects of their own insecure attachment on same-day relationship behaviours, their partner’s daily RM did, particularly for attachment avoidance. Our findings for next-day relationship behaviours, on the other hand, showed that lower (vs. higher) prior-day RM was associated with higher positive partner behaviours on the following day for avoidant individuals and those with anxious partners, showing this may be an attempt to “make up” for the previous day. These findings support the Attachment Security Enhancement Model and have implications for examining different forms of mindfulness over time and for mindfulness training.

Close relationships have the potential to fundamentally alter relationship partners’ self-concepts and, consequently, can impact individuals’ mental health. One type of relationship-induced self-concept change is self-expansion, which describes the cognitive reorganization of the self that can occur when individuals include aspects of their partner into the self, or when they share novel and challenging activities together. In the current research, we hypothesized that greater self-expansion would be associated with fewer depression symptoms. In support of this hypothesis, across four studies using cross-sectional, dyadic, daily diary, and longitudinal methodologies, we found that self-expansion was negatively associated with depression symptoms. This association was robust and remained a significant predictor of depression symptoms when controlling for demographic factors (gender, age, relationship length; Studies 1–4) and known risk factors of depression (dysfunctional attitudes, major life stressors, self-concept clarity; Study 2). Moreover, individuals’ self-expansion negatively predicted depression symptoms at the daily level (Study 3) and longitudinally over 9 months (Study 4). These results are the first to show the link between self-expansion and depression symptoms, suggesting that self-expansion may have robust benefits for individuals, beyond improving relationship dynamics.