<p>Interpersonal problems are broadly defined as chronic interpersonal performance issues which can comprise of interpersonal distress, unhelpful cognitive appraisals and behavioural responses to interpersonal situations and negative interpersonal outcomes (e.g. divorce). These are distinguished from interpersonal skills deficits which presume a person simply lacks the ability to act appropriately in interpersonal situations (Leising et al., 2011). Interpersonal problems can have adverse impacts on psychological wellbeing and are some of the most common reasons people present for psychological treatment (Mckay et al., 2012). This thesis investigated Young et al's (2003) early maladaptive schemas (EMS) from the schema therapy model and their relationship with interpersonal problems. In particular, this thesis attempted to clarify the existing evidence available for the relationship between EMS and interpersonal problems and develop a greater understanding for how EMS might be associated with interpersonal problems.</p> <p>Study one aimed to assess the magnitude of the association and potential moderators on the relationship between EMS and interpersonal problems. A total of 49 empirical studies were systematically reviewed and a meta-analysis was performed on reported correlations between EMSs and interpersonal problems using the PRISMA guidelines for systematic reviews. Study one found EMS to have a moderate positive association with interpersonal problems with EMS in the rejection and disconnection domain having the highest correlations with interpersonal problems. The strength of the association between EMS and interpersonal problems was found to be weaker in intimate relationships, when assessed by significant others and when assessing more specific types of interpersonal behaviour (e.g. aggression versus general problematic trait interpersonal tendencies). Limited experimental or longitudinal studies were found supporting a causal relationship between EMS on interpersonal problems.</p> <p>Study two designed a novel experimental paradigm for assessing the relationship between EMS and interpersonal problems. Study two consisted of 168 university students where degree of rejection was manipulated in a series of interpersonal vignettes. Study two aimed to assess if EMS moderated the casual relationship between different interpersonal contexts and the emotional, cognitive and behavioural responses to those contexts. Rejection was found to predict emotional, cognitive and behavioural responses and people reporting higher EMS reported higher levels of emotional distress and negative cognitions but no differences in behavioural responses. People reporting higher EMS also reported increased emotional distress and select negative cognitions as the degree of rejection in the interpersonal situation increased.</p> <p>Study three aimed to assess whether EMS are associated with trait tendencies to selectively attend to our environment and whether this was associated with increased interpersonal problems. This aim was achieved by assessing whether trait-mindfulness mediated the relationship between EMS and interpersonal problems. Utilising a sample of 117 university students, study three found both EMS and interpersonal problems to be negatively associated with trait-mindfulness. Decreases in select facets of trait-mindfulness were found to mediate the relationship between EMS and interpersonal problems including reduced tendencies to objectively describe and accept events in our environment without passing judgement.</p> <p>Together the findings of this thesis present consistent support for an association between EMS and interpersonal problems but find that the strength of this association might vary based on types of interpersonal relationships, measures of interpersonal problems and reporters used to assess interpersonal problems. This thesis provides one of the first experimental methods for assessing the relationship between EMS and interpersonal problems by manipulating the interpersonal situation (e.g. degrees of rejection) and assessing the changes in interpersonal responses to that situation. This thesis also argues that EMS might be associated with interpersonal problems by restricting attention, increasing emotional distress and negative cognitive reactions to interpersonal situations. This thesis found that EMS might be less likely to predict interpersonal behaviour and that interpersonal behaviour is more likely to vary based on the interpersonal situation.</p>