Two studies were conducted to identify variables associated with hypothetical infidelity forgiveness and promote forgiveness by manipulating implicit theories of relationships (ITRs; destiny/growth beliefs). Study 1 assessed the relationship between the type of behaviour, sex of the forgiver, ITRs and infidelity forgiveness. Study 2 investigated the causal relationship between ITRs and infidelity forgiveness (including attachment insecurity as a moderator). Results revealed that male participants forgave a partner's infidelity to a greater extent than female participants and that solitary behaviours were rated as most forgivable, followed by emotional/affectionate and technology/online behaviours, and sexual/explicit behaviours as least forgivable. Male participants (not female participants) induced to endorse growth beliefs forgave a partner's emotional/affectionate and solitary infidelity to a greater extent than those induced to endorse destiny beliefs; attachment insecurity moderated this relationship. These results have important implications for researchers and practitioners working with couples in distress.

The present study examined the relationship between dyadic interaction patterns and implicit theories of relationships (ITRs; deeply held beliefs about the nature of relationships) using a sample of N = 104 couples. We hypothesised that destiny beliefs would predict greater avoidance in conflict interactions, while growth beliefs would predict more constructive communication. Surprisingly, the results of the current study challenge the existing literature by indicating that neither destiny nor growth beliefs predict constructive communication or mutual avoidance for the couple. Further, while destiny beliefs were related to increased withdrawal in a demand-withdraw pattern, growth beliefs related to both demand and withdraw in a demand-withdraw pattern. These findings suggest that assessing the relationship between ITRs and communication patterns at the couple level introduces complexity that is underexplored in the current literature on implicit theories of relationships.