It is not difficult to imagine how an individual's personality could impact their
social behaviour.Through the second perspective, the
study goes beyond examining stable trends in social behaviour to also investigate the
ability of the pathological personality traits to predict indices of instability in social
behaviour, which may represent important manifestations of interpersonal impairment.This chapter outlines the theoretical and methodological foundations for this
project, including a review of how personality dysfunction has been conceptualized
throughout history, the research findings that support the alternative DSM-5 model of
personality disorder, the interpersonal circumplex model of social behaviour, and the use
of intensive repeated measures in naturalistic settings to assess real-world social
behaviour.For example, empirical findings indicate that personality
plays an important role in the overarching structure of psychopathology (Kotov et al.,
2017; Wright & Simms, 2015), and others have asserted that much of psychopathology is
expressed within interpersonal relationships (e.g., Hopwood et al., 2013; Seivewright et
al., 2004; Sullivan, 1953).A 10-
day procedure using intensive repeated measures in naturalistic settings (IRM-NS) was
used to assess targets' social behaviour; targets described their behaviour in everyday
interactions, aligning with methods used in past literature (Moskowitz, 1994).Understanding how the pathological personality traits of the alternative model for
personality disorders relate to patterns of social behaviour represents an important test of
this new approach, which the American Psychiatric Association regards as an 'emerging
model' that requires additional empirical review before full adoption.As will be shown, excessive intrapersonal variability appears to be a marker of
dysfunction, and thus understanding how the traits relate to these markers represents an
important investigation of how interpersonal impairment may be manifested.Accordingly, such
pathological personality traits play a central role in the alternative model for personality
disorders listed in the fifth edition of the Diagnostic and Statistical Manual of Mental
Disorders (DSM-5; American Psychiatric Association, 2013).Regarding the first perspective, this study is
one of the first to compare the predictive validity of self- versus informant-reports of
pathological personality traits, using an ecologically valid and methodologically rigorous
measure of social behaviour as the outcome variable.As will be reviewed, the link between personality dysfunction and
social behaviour is well established in the broader literature, but few studies have
examined the connections between the pathological personality traits of this model and
social behaviour in a multifaceted way.However, replace 'agreeable' with
'antagonistic' or 'manipulative' and the picture soon changes.