Degree Name

Doctor of Psychology (Clinical)


School of Psychology


Pathological lying, otherwise referred to as pseudologia fantastica, has not been adequately defined, validated or conceptually anchored in a way which provides a sound basis for its measurement, or which allows for conclusions to be produced and applied to real-life cases. The absence of a clear, consistent, and scientifically ratified definition impedes and, it could be argued, prevents systematic, empirical research into this phenomenon. The aims of this thesis, therefore, are to elucidate and stabilise the construct’s elemental features, provide an operational definition, and identify valid and distinguishable diagnostic criteria. To achieve these aims four separate but complementary investigations were undertaken. The first involved a review and meta-analysis of the existing literature, with a particular focus on published definitions of pathological lying. Thirty-two definitions were identified, cross-analysed and reduced into one synoptic definitional description. This process corroborated that while no universally endorsed definition exists it is a construct that has global recognisability. The second investigation thematically analysed 64 international and cross-generational case studies. The outcome was a nomothetic profile of pathological lying outlining the construct’s core symptom and aetiological constellations. An important finding was that there was enough between case-study consistency to support the stance that pathological lying represents an autonomous condition underpinned by a number of key behavioural and cognitive markers. The third and fourth investigations formed the empirical arm of this thesis, capturing current views of pathological lying as held by practising mental health clinicians. Using a semi-structured interview protocol developed by a targeted focus group of psychology experts, participants were asked to outline their experiences with pathological liars. The qualitative data extracted from these interviews was thematically analysed, providing an integrated account of the construct’s core features. The collective findings of all four investigations indicate pathological liars represent a sub-population, which can be distinguished from other clinical and nonclinical populations. A set of diagnostic criteria modelled on a DSM framework was generated from the data. Systematic comparisons were drawn between pathological lying and a target group of DSM-IV-TR diagnoses, providing an overview of construct divergence and convergence. Limitations and directions for future research were discussed.