A further advantage of the Big Five was its predictive power because it arguably captured the five most fundamental dimensions of personality, it was able to predict a range of important outcomes including academic performance (Poropat, 2009), job performance (Barrick & Mount, 1991 Hurtz & Donovan, 2000), counterproductive work behaviour (Dalal, 2005), wellbeing (Anglim & Grant, 2016 Steel, Schmidt, & Shultz, 2008 Sun, Kaufman, & Smillie, 2017), and mortality (Bogg & Roberts, 2004). This supported theoretical development and meta‐analytic synthesis. It also served as an organising framework for the proliferation of traits because most of these traits aligned with one or more of the Big Five dimensions. The Big Five was influential and necessary in personality psychology because it provided five broad, empirically derived traits that collectively accounted for the major dimensions upon which individuals differ: extraversion, agreeableness, conscientiousness, neuroticism, and intellect/openness (Digman, 1990 Goldberg, 1990). Partially in response to this proliferation, the Big Five emerged in the early 1990s as a unifying taxonomy of personality traits. This proliferation of traits in the absence of an organising framework resulted in a fragmented personality trait literature, where it was difficult to synthesise research findings.

By the early 1990s, measures had been developed for hundreds of personality traits, many of which were developed by different research teams and varied only slightly from each other. Indeed early research on personality was characterised by a proliferation of such traits and associated measurement tools, with researchers often proposing new, or alternative versions of existing traits in order to determine or ‘discover’ the trait underlying some phenomena of interest (e.g., leadership, see Bass & Stogdill, 1990). Since there are many stable aspects of human behaviour, there are also many potential traits researchers could propose to capture these aspects. Personality traits are termed ‘narrow’ when they relate to a specific set of tendencies, and to more concrete behaviours (e.g., talkativeness, risk‐taking), and are termed ‘broad’ when they relate to a more general set of tendencies, and to more highly abstracted aspects of behaviour and experience (e.g., extraversion).

They are frequently used by researchers to describe and classify individuals (e.g., optimistic, ambitious, aggressive, etc.) often in order to explain and predict some external phenomena of interest (e.g., academic performance, Poropat, 2009). Personality traits can be defined as relatively stable patterns of thoughts, feelings and behaviours on which people differ (McCrae & Costa, 1995).

Hexio personality test