What is personality?

Brief historical review

According to Encyclopedia Britannica, personality psychology was born in the 1930:ies when its founding fathers such as Gordon Allport and Henry Murray published their textbooks (Allport, 1937; Murray, 1938). The field encountered hard criticism in 1970-1980 when Walter Mischel presented in his highly influential book empirical results according to which person factors were weak predictors of behavior (Mischel, 1968). The person-situation debate ended in at least a partial victory for the person viewpoint (Kenrik & Funder, 1988).

The success of the person viewpoint was significantly enhanced by the advent of the so-called big five framework. With roots in cataloging of person-descriptive words in dictionaries and based on statistical factor analysis, the forming of measurement scales ended in presenting Conscientiousness, Extraversion, Agreeableness, Openness and Neuroticism or Emotional stability as both reliably measured and broadly predictive personality traits. The framework did not generate any truly novel traits but assembled the diverse earlier traits from the fifty-year trait research tradition into five broad traits. Many of the preceding narrower traits clustered in factor analysis onto the five big traits as their subtraits or facets.

After the low-tide period of the debate years, the advent of the Big Five framework has integrated trait conceptualizations, strengthened the scientific standing of the entire discipline and given a general boost to personality research. In addition to the meta-analyses predicting work performance, a particularly significant finding using large longitudinal samples is the remarkable stability of personality from early childhood to old age. The stability (r=.74) is on a par with that of the IQ. However, the interesting finding is that the stability plateau of intelligence is attained at the 6-8 year age but personality reaches a stability plateau only after the age of 50 (Roberts & DelVecchio, 2000). The newest meta-analysis (Bleidorn et al., 2022), extended with samples after 2005 (close to 180.000 individuals) shows somewhat lower overall stability, an earlier, already at age 25 stabilizing plateau and throughout life improving emotional stability. In addition to stability, results point to malleability of personality, see in the following.

The most important research of the two last decades concerns health and well-being. Research using large longitudinal samples have shown that among other things, personality is a stronger predictor of longetivity and mortality than socio-economic status (Roberts et al., 2007). A recent prestigious publication by researchers from all over the world urges to pay attention to the social political significance of personality and give up the traditional erroneous notion that personality is unchanging (Bleidorn et al., 2019). Psychotherapy has been shown to lead to personality change (DeFruit et al., 2006). In addition to maturation, major life events such as marriage, birth of the first child, first job, the death of a family member and unemployment can cause enduring personality changes (Specht et al., 2011). A recent meta-analysis (Buhler et al. 2024) brings partial confirmation to the previous by bringing forth graduation, first job, new relationship, marriage and divorce as personality changing life experiences.

The influence of life experiences and genetic factors on personality was studied by combining twin study samples from over 7000 individuals in the age period of 14 to 90 from Croatia, Finland, Germany and UK. The results showed that the influence of life experiences increased while the influence of hereditary factors decreased with age (Kandler et al., 2021).

Traits and goals

Drawing upon the Encyclopedia of Psychology, American Psychological Association APA defines personality as referring to individual differences in characteristic patterns of thinking, feeling and behaving (APA, 2000). The discipline's leading scholars define personality much in line with the previous. As is evident, the discipline is characterized by its immense diversity of person factors, individual differences have been sought among nearly all psychological processes. In Mayer's words: "personality psychologists have their fingers in everyone else's pie" (Mayer, 1995, 489).

The numerous and highly diverse personality factors have been condensed into two main classes: traits and goal-oriented dispositions (Alston, 1975; Buss & Craik, 1984). Personality traits describe obseved habitual behavior recurring across situations. That is, personality traits are summaries of observed behavior tendencies. They are in direct relation to behavior without a causal explanation. Extraversion predicts extraverted behavior.

Goal-oriented factors in turn describe directional behavior. They are situation specific, directing behavior through situational conditions. Motives, needs and vocational interests are the most well-known goal-oriented dispositions. Motives and needs direct behavior in conjunction to appropriately arousing factors in the environment (eg., jobs). Vocational interests steer behavior in environments (eg., occupations, jobs) which incorporate corresponding vocational interests.

The roots of personality traits are in Gordon Allport's (1937) theorizing which gave birth to the extensive tradition of research in personality traits. The Big Five trait framework has currently attained wide popularity, a dominant position in some applied fields and has served as the basis for development of a multitude of tests, standardized self-report questionnaires. The most well-known test of the five factor framework and its close variants (eg., HEXACO) is the NEO-PI-R (Costa & McRae, 1992). Numerous meta-analyses in different application fields have been published. Meta-analyses on work and academic performance have been published by Barrick & Mount (1991), Hurtz & Donovan (2000) and Zell & Lesick (2021) incorporating over half a million subjects. Perhaps the most interesting finding in this "superanalysis" is that work and academic performance are predicted by different traits.

Motives and needs share with traits a long history in personality psychology. The theoretical roots lie in Henry Murray's taxonomy of nearly thirty needs (eg., need for achievement) and need-arousing environmental "press" (1938). Also mentioned should be David C. McClelland's theory of "three big" motivations purported to underlie the taxonomy. An important tenet of the theory of achievement, power and affiliation motivation is the division to implicit, nonconscious and explicit, self-reportable motives (McClelland et al., 1989, Schultheiss, 2008, 2021). The most widely known need-motive questionnaire is the PRF (Jackson, 1984). Meta-analyses on predicting behavior from motives include Spangler (1992), Collins et al., (2004) and Van Iddekinge et al. (2018).

Goal-directed dispositions describing directional behavior include vocational interests which have recently drawn renewed attention in work psychology. The focus has been particularly on Holland's (1997) theory of vocational personality. The RIASEC model targets at individual differences among the six vocational interests: (R) Realistic, (I) Investigative, (A) Artistic, (S) Social, (E) Enterprising and (C) Conventional-detailed. The same terms are used in describing people and vocations with the goal of matching them together. Vocational interests were for a long time considered useful only in occupational choice and career coaching. Three meta-analyses indicate that they also predict performance at work even better than personality traits (eg., Nye et al., 2017).

The division to observable traits and internal motives in people is age-old, evident in descriptions of human character by writers from early antiquity, in literature and in everyday speech. The same division is reiterated in the founding years of academic personality psychology. Coincidence or not, both Allport the founding father of the trait theory of personality and Murray, the creator of the need-motive theory of personality worked at the same time in the same Harvard University.

Personality traits and motives, needs and interests are different perspectives on personality. They are not rivalling nor better than the other. They are like apples and oranges: both are good fruits but different inside. They provide answers to different questions and are useful for different purposes. Traits describe the individual's general behavior trends attractive in their simplicity. Goal-directed factors, linked to situations, are slightly more complicated but useful for understanding of the individual.

Traits and motives have in meta-analyses shown to predict behavior with roughly equal strength. They are complementary perspectives and it is unfortunate that the two big research traditions of personality psychology have lived in their own silos. Fruitful integration is exemplified in a longitudinal study with large datasets where the joint use of traits and motives resulted in significant prediction increments to what was achieved with use of only one disposition class (Winter et al., 1998). A more serious case of the separate lives of the diverse personality dispositions concerns ways of thinking.

Personal ways of thinking

Individual ways of thinking or cognitive styles have led an isolated orphan's life, occasionally seen as parts of personality and occasionally of intelligence. This, despite that many leading scholars, not to mention the American Psychological Association incorporate thinking in their definitions of personality. The heyday of cognitive style research dates back to the period 1950-1970 and its well-known exemplars include individual differences in locus of control and field dependence-independence. No clear reason is available for the post-period waning of interest but this obviously relates to the modest empirical results at face of the preceding expectations.

It is noteworthy that despite APA's and the leading scholars' definitions encompassing the three main psychological processes, research focus has been heavily on observable behavior. It is also paradoxical that MBTI (Myers & Briggs, 1985), the most widely used personality test in the world measures personality types based essentially on individual thinking processes. Occasionally treated unfairly by the academic community, the MBTI stands for some in the larger audience as what is meant by personality.

There has appeared renewed interest in ways of thinking during the last three decades. Particularly so concerning the so-called dual-process theories (Evans & Stanovich, 2013), made known to the larger audience by the Nobel laureate Daniel Kahneman's book on "fast and slow" thinking (Kahneman, 2011). The split to intuitive and analytical thinking serves also as basis for a whole theory and test of personality (Epstein, 2013; Epstein et al. 1996).

However, the most important reason for renewed attention to ways of thinking relates to the current transition to data-centric society. Digitalization and artificial intelligence are already part of the everyday living and citizens need to understand and handle information. Among the top ten skills needed in 2025, listed by the World Economic Forum, the first five, from analytical thinking to creativity, pertain to thinking processes. Along the disruption of work, "doing" things is shifting over to algorithms and robots. Instead of "doing", the great opportunity for humans remains in planning and problem solving, less any more in "doing" things. Ways of thinking are a "pie" for personality researchers to make a great contribution.

Back to situations

Situational factors have also re-entered the agenda in personality psychology. In the aftermath of the person-situation debate proponents of the situation perspective acknowledged the existence of personality factors but argued that their influence depends on each situation (Mischel & Shoda, 1995).

The significance of situational interaction in production of behavior is also growingly recognized by trait researchers, particularly those studying work performance. The so-called activation model of personality traits (Tett & Burnett, 2003) coincides much with Henry Murray's early taxonomy according to which environmental "press" arouse individuals' needs to behave in accordance to the "press". The activation model states that traits become activated by environmental cues. At work, such environmental cues may derive from the organization's culture, leadership practices and ultimately to requirements of each job.

Shaffer and Postlethwaite published a meta-analysis (2012) showing that personality tests with their scale items or instructions framed specifically to reference work-specific behaviors reached an average validity of .24, whereas the noncontextualized, general personality tests reached only a .11 level. Situations were taken even more strongly into account in a meta-analysis on vocational interests. The results showed that the match between an individual's main interest and that of the vocation resulted in significant increments in prediction of work performance (Nye et al., 2017).

The dynamic, changing quality of situations has also attracted research. An entire European country's 1997 cohort of medical students were followed throughout their seven-year medical school career (Lievens et al., 2009). Personality factors predicted GPA better, the further the education progressed, from .18 level in the starting phase to the .45 validity level in the ending phase. In medical education as in other fields the beginning phase has its emphasis on basic science education that is, acquisition of knowledge for which personality is not viewed to be essential. But as the education progresses to application of knowledge, to simulation exercises, to real world complex problem solving and clinical internships, personality is viewed as exerting significant influence on performance.

Instead of maximizing the predictive power of personality factors, a more important reason for increased focus on situations is to better understand the evolvement of behavior enabling more comprehensive development efforts. The person-situation constellation is present in many, if not all personality related research, for example in work psychology from research in job competencies to understanding job burnout phenomena.

Rauthmann and colleagues are calling for a more focused approach to situational characteristics and present their own taxonomic approach (Rauthmann et al., 2014). Besides personality factors, a recently published study covering 62 countries, 15.000 respondents and 42 languages mapped out situations' general psychological features with a specifically developed assessment method (Lee et al., 2020). Work psychology hasn't seen a major taxonomy on psychological work environments after Holland's RIASEC model (1997) perhaps with the exception of cultural factors. The sprung interest in situations' characteristics is evidenced in the concept of "psychological situations" introduced in a very recent handbook (Rauthmann, Sherman & Funder, 2020). Overall, psychological study must growingly focus on persons in situations. This appears as almost self-evident to professional psychologists doing recruitment, but it is a newer theme in academic research.