Personality

Personality refers to the enduring patterns of thoughts, feelings, and behaviours that distinguish one individual from another. This is why you will also see it referred to in psychological circles as personality and individual differences. In the context of psychological assessment, personality is viewed as a set of relatively stable traits that influence how a person interacts with their environment, processes information, and responds to social stimuli. Put simply, personality is essentially how we differentiate each other without relying on physical descriptions, and instead on actions, behaviour, and words.

When considering personality in the context of assessments or inventories, these are designed to quantify the internal constructs of personality using standardised frameworks, derived from established and fairly complex statistical methods and processes, to be able to understand and compare people in as accurate and objective a way as possible. Key aspects of personality and its measurement have been explored and discussed at length through research and publications through more than 100 years of work.

Trait versus Type

A long running differentiation between conceptualisations and models of personality delineates personality 'types' - a set of groupings or categories of personality type that attribute a full set of descriptions and characteristics to an individual in that group, and 'traits' - a full set of behavioural traits that each apply to everybody, where an individual will sit somewhere on the trait spectrum, which outlines a behaviour at one end, with its equal and opposite at the other (e.g. introversion versus extraversion).

Type-based personality inventories have a tendency to be more popular among participants and users, because they are relatively easy to understand and speak to, and to discuss with others in terms of differences, similarities, and broader behavioural patterns among a group of people. A good example of this is the use of DiSC, or MBTI (Myers-Briggs Type Indicator). For this reason, Type-based personality assessments are routinely implemented in group or team processes for understanding the concept of individual differences and mapping these out relatively easily in a team sense, and in individual use for self-discovery and reflection.

With this said, Type-based inventories can fall down when it comes to reliability and accuracy, and tend not to be guided by the research and statistical data in their development, demonstrating that the nuances and intricacies of human personality are much too complex and challenging to squeeze into groupings in such a way. So, Type-based inventories ae best avoided for uses where outcomes will determine real decisions about employment or opportunities.

Trait-based inventories are much more popular among psychologists and practitioners, who do employ Trait-based inventories for recruitment and selection, research, and related uses where accuracy is critical. The psychological research has consistently pointed to a Trait-based personality structure for more than 100 years now, where the research-based and heavily replicated Big Five model of personality, and each of the sub-factors that sit under those five primary factors, are represented by a behaviour trait spectrum with each end anchored by equal and opposite behaviours.

These tests often provide a percentile score, or classification for a percentile score (Below Average, Far Above Average, etc) for each factor, which can realistically be up to 35 different percentile scores depending on the inventory. This obviously dramatically improves the precision and reliability of the personality results, however with this power of detail comes difficulty in interpreting these outcomes efficiently, and in easily comparing results together meaningfully, without a psychological practitioner. For this reason Type-based assessments are often preferred as a fit-for-purpose tool for team building and team strategy sessions, and similar processes.

Predicting behaviour

Personality describes common and enduring behaviour, and therefore personality assessments have a primary purpose of predicting how an individual will behave in the future, based on certain scenarios or interactions. For this purpose it is relatively powerful as a prediction tool. In the context of recruitment and selection, this refers to the manner in which a candidate may direct their energy, the manner in which they solve problems or choose to interact with others, how they react to stressful circumstances or interpersonal challenges, and placed in combination with other assessments to measure related but distinct construct such as cognitive ability, to get as comprehensive a view and understanding of the individual as possible and how well they will fit with the existing team and culture, and role requirements. 

Where some criticism is levelled at personality as a means of predicting behaviour is the fact that personality outcomes overall are found to predict behaviour with a Pearson's correlation coefficient of 0.3, which in strict statistical terms is not extraordinarily strong (correlations lay on a spectrum from -1 for perfect negative correlation, to 0 for no correlation, to 1 as a perfect correlation). However, this being the real and very complex and nuanced world, 0.3 is actually quite impressive considering the sheer depth of external and contextual factors outside of our own temperaments that can impact our reactions and behaviour. While it is not a perfect predictor, considering the complexity of the average human being and the world they occupy, it is among the best methods that we have. 

Stability and change

Personality also happens to be relatively stable and steady over time. Being a product of our inherent genetic temperament and the environment and context in which we are raised (both nature and nurture in combination), it is not surprising that personality is stable over time, maintaining its core features but maturing and developing over time based on experience. Major life events and significant stressors can also have an impact on personality and common behaviours over time. It has also been found with some longitudinal studies that over longer time periods older adults can become more 'agreeable' (from the Big Five factor 'Agreeableness'), and also less 'open' (from the Big Five factor 'Openness to Experience'). This is an average effect though over a very large sample of people over time, and not guaranteed to be reflective of everybody.

By utilising objective, evidence-based metrics, personality assessments provide a data-driven way to understand individual differences, which is essential for optimising team composition, leadership development, organisational culture, and individual insight and reflection.