<p>Many researchers contend that the intra-individual configuration of multiple traits, as compared to isolated trait dimensions, more effectively capture personality functioning at the level of the individual. Moreover, it is argued that by identifying subsets of individuals with similar trait-profiles, we can shed light on the generative mechanisms that underlie the expression and functioning of personality. Notably, self-regulatory systems of ego-resiliency and ego-control, as developed by Block and Block, comprise a valuable theoretical foundation for the development and interpretation of personality types. However, much of the literature on this topic is theoretically ambiguous, and is afflicted with inconsistent empirical outcomes across studies. The focus of the present thesis is to advance the empirical assessment and theoretical interpretability of personality profiles. More particularly, comparisons between three and four profile solutions are at the core of the current investigations. These competing models reflect differing interpretations of ego-domains; the three profile model embodies a proposed curvilinear relationship between the two constructs, whereas the four profile model emphasises the roles of ego-resiliency and ego-control as distinct mechanisms with unique outcomes. In Study 1, Latent Profile and Latent Transition Analyses were conducted using the Six-Factor Model of personality. Three and four profile solutions were developed and compared using measures of model fit, profile interpretability, longitudinal stability, and predictive ability. In Study 2, the replicability of both solutions when using the Five-Factor Model was examined, along with the comparative value of the Six- as opposed to Five-Factor Model in profile identification. Finally, in Study 3, the interpretability of the four profile solution as reflecting differentiated domains of ego-functioning was assessed using established measures of ego-resiliency and ego-control. Across all three studies, profiles were considered using a novel approach utilising both continuous and categorical methodologies. Rather than treating profiles as entirely discrete groupings of personality functioning, the present investigation considers convergence with prototypical profiles in terms of degree. The current findings provide support for the four profile solution as a more coherent and theoretically validated model as compared to the three profile solution. Specifically, although both solutions demonstrated good fit and longitudinal stability, the four profile solution was associated with more theoretically interpretable outcomes. These findings were consistent when using both the Six- as well as Five-Factor Model of personality; however, omission of the sixth trait resulted in a reduction in profile precision and explanatory power. Finally, in Study 3, selected exemplars of the four profile solution converged onto theoretically consistent domains of high/low ego-resiliency and ego-control. Block and Block’s model of ego-resiliency and ego-control provides a clear unifying framework for the intra-individual structuring of a four profile configuration of traits. Ego-constructs are flexible self-regulatory mechanisms that develop through reciprocal person-environmental transactions. The current results are therefore suggestive of a hierarchical relationship between ego-domains and personality traits, whereby traits form the basic parameters of a dynamic self-regulatory system. Moreover, the combination of continuous and categorical methodologies presently used strengthens the conclusions and arguments in this thesis.</p>
USING THE FIVE FACTOR MODEL TO STUDY PERSONALITY CONVERGENCE ON STUDENT ENGINEERING DESIGN TEAMS
