Who are you?
It’s a simple question, but it can be difficult to answer.
You could answer with your name, your job title, your place in relation to your family, your hobby or passion, where you’re from, or a description of your beliefs and values.
There are billions of humans with billions of answers to this question, and each one can tell a different story about who they are. While we may have a lot in common with our fellow humans, like race, religion, sexual orientation, skills, and eye color, there is one thing that makes us each unique: personality.
You can meet hundreds, thousands, or even tens of thousands of people, but no two will be exactly the same.
This article contains:
What is Personality?
Personality is an easy concept to grasp for most of us. It’s what makes you “you”. It encompasses all the traits, characteristics, and quirks that set you apart from everyone else.
In the world of psychology research, personality is a little more complicated. The definition of personality can be complex, and the way it is defined can influence how it is understood and measured.
According to the researchers at the Personality Project, personality is:
“the coherent pattern of affect, cognition, and desires (goals) as they lead to behavior” (Revelle, 2013).
In the words of the American Psychological Association (APA), personality is:
“individual differences in characteristic patterns of thinking, feeling, and behaving” (APA, 2017).
However you describe personality, it’s clear that personality has a big impact on life. In fact, personality has been found to correlate strongly with life satisfaction (Boyce, Wood, & Powdthavee, 2013). With such a large potential impact on life, it’s important to have a reliable way to conceptualize and measure personality.
The most prevalent personality framework is the “Big Five,” or the five-factor model of personality. Not only does this theory of personality apply in multiple countries and cultures around the world, there is a valid and reliable assessment scale for measuring the five factors.
But to understand how we got to the Big Five, we have to go back to the beginning of personality research.
Personality Research: A Brief Review
The history of personality research can be roughly divided into seven periods, characterized by different prevailing theories and underlying philosophies.
It seems that as long as there have been humans with personalities, there have been personality theories, classifications, and systems.
Hippocrates (the father of the Hippocratic Oath, which health workers still recite to this day) hypothesized two poles on which temperament could vary: hot vs. cold and moist vs. dry. This idea results in four possible combinations (hot/moist, hot/dry, cold/moist, cold/dry) called “humors” that were thought to be the key factors in both health issues and personality peculiarities.
Later, Plato suggested a classification of four personality types or factors: artistic, sensible, intuitive, and reasoning. His renowned student, Aristotle, proposed a similar set of factors that could explain personality: iconic (or artistic), pistic (or common sense), noetic (intuition) and dianoetic (or logic).
While Aristotle mused on a possible connection between the physical body and personality, this connection was not a widespread belief until the rise of phrenology and the shocking case of Phineas Gage.
Phrenology and Phineas Gage
Phrenology is a pseudoscience, or “science” that is not based on any actual, verifiable evidence, that was promoted by a neuroanatomist named Franz Gall in the late 18th century. This pseudoscience hypothesizes a direct relationship between the physical properties of different areas of the brain (such as size, shape, and density) and opinions, attitudes, and behaviors.
While this pseudoscience was debunked relatively quickly, it marked one of the first attempts to tether the physical brain to the individual’s traits and characteristics. The disappointment of phrenology’s failure to provide solid evidence of this connection did not last long.
In 1848, an incident occurred that forever changed the mainstream views on the interconnectivity of the brain and personality. A railroad construction worker named Phineas Gage suffered a terrible accident on the job, in which a premature detonation of explosive powder sent a 3.6 foot (1.1 m), 13.25 pound (6 kg) iron rod into Gage’s left cheek, through his head, and out the other side.
Gage, astonishingly, survived the incident with only a wound where the rod penetrated and blindness in his left eye. However, his good fortune ended there. His friends reported that his personality completely changed after the incident – suddenly he could not keep appointments, showed little respect or compassion for others, and uttered “the grossest profanity.” He died in 1860 after suffering from a series of seizures (Twomey, 2010).
This was the first case that showed clear evidence of a link between the physical brain and personality, and it gained national attention. Interest in the psychological conception of personality spiked, leading to the next phase in personality research.
Sigmund Freud is best known as the father of psychoanalysis, an intensive form of therapy that digs deep into an individual’s life, especially their childhood, to understand and treat their psychological ailments.
However, he also did extensive work on personality, some of which is probably familiar to you. One of his most fleshed out theories held that the human mind consists of three parts: the id, the ego, and the superego.
The id is the primal part of the human mind that runs on instinct and aims for survival at all costs. The ego bridges the gap between the id and our day-to-day experiences, providing realistic ways to achieve the wants and needs of the id and coming up with justifications and rationalizations for these desires. The superego is the portion that represents humans’ higher qualities, providing the moral framework that humans use to regulate their baser behavior.
While there has not been much evidence found to support Freud’s idea of a three-part mind, this theory did bring awareness to the fact that at least some thoughts, behaviors, and motivations are unconscious. We began to believe that a person’s behavior was truly the tip of the iceberg when assessing their attitudes, opinions, beliefs, and unique personality.
Jung was influenced by his mentor Freud, but ultimately came up with a much different system of personality. Jung believed that there were some overarching “types” of personality that each person could be classified into based on dichotmous variables.
For example, Jung believed that individuals were firmly within one of two camps:
1) Introverts – gain energy from the “internal world” or from solitude with the self
2) Extroverts – gain energy from the “external world” or interactions with others
This idea is still extremely prevalent today, and research has shown that this is a useful differentiator between two relatively distinct types of people. Of course, today’s psychologists generally have a more fluid view of the dichotomy, and see it as a spectrum rather than strictly bipolar.
Further, Jung identified what he found to be four essential psychological functions:
He believed that each of these functions could be experienced in an introverted or extroverted fashion, and that one of these functions is more dominant than the others in each person.
Jung’s work on personality had a huge impact on the field of personality research, an impact that is still being felt today. In fact, the popular Myers-Briggs Type Indicator® test is based in part on Jung’s theories of personality.
Abraham Maslow and Carl Rogers
Abraham Maslow built on the idea that Freud brought into the mainstream, that at least some aspects or drivers of personality are buried deep within the unconscious mind.
Maslow hypothesized that personality is driven by a set of needs that each human has. He organized these needs into a hierarchy, with each level generally requiring fulfillment before a higher level can be fulfilled.
The pyramid is organized from bottom to top here, beginning with the most basic need (McLeod, 2007):
- Physiological needs (food, water, warmth, rest)
- Safety needs (security, safety)
- Belongingness and love needs (intimate relationships, friends)
- Esteem needs (prestige and feelings of accomplishment)
- Self-actualization needs (achieving one’s full potential, self-fulfillment)
Maslow believed that all humans aimed to fulfill these needs, usually in order from most basic to most transcendent, and that these motivations result in the behaviors that make up a personality.
Carl Rogers built off of Maslow’s work, agreeing that all humans strive to fulfill needs, but disagreeing that there is a one-way relationship between striving towards need fulfillment and personality. Rogers believed that the many different ways humans utilize in trying to meet these needs spring from personality, rather than the other way around.
Rogers’ contributions to the field of personality research signalled a shift in thinking about personality. Personality was starting to be seen as a collection of traits and characteristics that were not necessarily permanent rather than a single, succinct construct that can be easily described.
Multiple Personality Traits
In the 1940s, psychologist Hans Eysenck built off of Jung’s dichotomy of introversion versus extroversion. He hypothesized that there were only two defining personality traits: extroversion and neuroticism. Individuals could be high or low on each of these traits, leading to four key types of personalities.
Eysenck also connected personality to the physical body in a much more extensive way than most previous personality researchers and philosophers. He posited that differences in the limbic system resulted in differences in hormones and hormonal activation. Those who were already highly stimulated (introverts) would naturally seek out less stimulation while those on the lower end (extroverts) would search for greater stimulation.
Eysenck’s thoroughness in connecting the body to the mind, or personality, pushed the field toward a more scientific exploration of personality based on objective evidence rather than solely philosophical musings.
Lewis Goldberg may be the most prominent researcher in the field of personality psychology. His groundbreaking work whittled down Raymond Cattell’s 16 “fundamental factors” of personality into five primary factors, similar to the five factors found by fellow psychology researchers in the 1960s.
The five factors Goldberg identified as primary factors of personality are:
- Openness to experience
This five factor model caught the attention of two other renowned personality researchers, Paul Costa and Robert McCrae, who confirmed the validity of this model. This model was termed the “Big Five” and launched thousands of explorations of personality within its framework, across multiple continents and cultures and with a wide variety of populations.
The Big Five brings us up to about the current era in personality research. The Big Five theory still holds sway as the prevailing theory of personality, but some of the salient aspects of current personality research include:
- Conceptualizing traits on a spectrum instead of as dichotomous variables
- Contextual personality traits (exploring how personality shifts based on environment and time)
- Emphasis on the biological bases of personality and behavior
Since the Big Five is still the most mainstream and widely accepted framework for personality, the rest of this piece will focus exclusively on this this framework.
OCEAN: The Five Factors
As noted above, the five factors grew out of decades of personality research, growing from the foundations of Cattell’s 16 factors and becoming the most accepted model of personality to date. This model has been translated into several languages and applied in dozens of cultures, resulting in research that not only confirms its validity as a theory of personality but also establishes its validity on an international level.
These five factors do not provide completely exhaustive explanations of personality, but they are known as the “Big Five” because they encompass a large portion of personality-related terms. The five factors are not necessarily traits in and of themselves, but factors in which many related traits and characteristicsfit.
For example, the factor agreeableness includes terms like generosity, amiability, and warmth (on the positive side) and aggressiveness and temper (on the negative side). All of these traits and characteristics, and many more, make up the broader factor of “agreeableness.”
Below we explain each factor in more detail, with examples and related terms to help you get a sense of what aspects and quirks of personality these factors cover.
A popular acronym for the Big Five is “OCEAN.” The five factors are laid out in that order here.
Openness to Experience
Openness to experience has been described as the depth and complexity of an individual’s mental life and experiences (John & Srivastava, 1999). It is also sometimes called intellect or imagination. Openness to experience concerns an individual’s willingness to try to new things, to be vulnerable, and the ability to think outside the box.
Common traits related to openness to experience include:
- Wide variety of interests
- Preference for variety
An individual who is high in openness to experience is likely someone who has a love of learning, enjoys the arts, engages in a creative career or hobby, and likes meeting new people (Lebowitz, 2016a).
An individual who is low in openness to experience probably prefers routine over variety, sticks to what they know, and prefers less abstract arts and entertainment.
Conscientiousness is a trait that can be described as the tendency to control impulses and act in socially acceptable ways, behaviors that facilitate goal-directed behavior (John & Srivastava, 1999). Conscientious people excel in their ability to delay gratification, work within the rules, and plan and organize effectively.
Traits within the conscientiousness factor include:
- Hard working
Someone who is high in conscientiousness is likely to be successful in school and in their career, to excel in leadership positions, and to doggedly pursue their goals with determination and forethought (Lebowitz, 2016a).
A person who is low in conscientiousness is much more likely to procrastinate, to be flighty, impetuous, and impulsive.
This factor has two familiar ends of the spectrum: extroversion and introversion. It concerns where an individual draws their energy and how they interact with others. In general, extroverts draw energy or “recharge” from interacting with others, while introverts get tired from interacting with others and replenish their energy from solitude.
The traits associated with extroversion are:
- Socially confident
People high in extroversion tend to seek out opportunities for social interaction, where they are often the “life of the party.” They are comfortable with others, gregarious, and prone to action rather than contemplation (Lebowitz, 2016a).
People low in extroversion are more likely to be people “of few words,” people who are quiet, introspective, reserved, and thoughtful.
This factor concerns how well people get along with others. While extroversion concerns sources of energy and the pursuit of interactions with others, agreeableness concerns your orientation to others. It is a construct that rests on how you generally interact with others.
The following traits fall under the umbrella of agreeableness:
People high in agreeableness tend to be well-liked, respected, and sensitive to the needs of others. They likely have few enemies, are sympathetic, and affectionate to their friends and loved ones, as well as sympathetic to the plights of strangers (Lebowitz, 2016a).
People on the low end of the agreeableness spectrum are less likely to be trusted and liked by others. They tend to be callous, blunt, rude, ill-tempered, antagonistic, and sarcastic. Although not all people who are low in agreeableness are cruel or abrasive, they are not likely to leave others with a warm fuzzy feeling.
Neuroticism is the one Big Five factor in which a high score indicates more negative traits. Neuroticism is not a factor of meanness or incompetence, but one of confidence and being comfortable in one’s own skin. It encompasses one’s emotional stability and general temper.
These traits are commonly associated with neuroticism:
Those high in neuroticism are generally given to anxiety, sadness, worry, and low self-esteem. They may be temperamental or easily angered, and they tend to be self-conscious and unsure of themselves (Lebowitz, 2016a).
Individuals who score on the low end of neuroticism are more likely to feel confident, sure of themselves, and adventurous. They may also be brave and unencumbered by worry or self-doubt.
The Trait Network
How personality traits are connected to each other and just about everything else.
Research has shown that these factors are interconnected, and connected to just about everything else as well! Because the Big Five are so big, they encompass many other traits and bundle related characteristics into one cohesive factor.
Openness to Experience
Openness to experience has been found to contribute to likelihood of obtaining a leadership position, likely due to the ability to entertain new ideas and think outside the box (Lebowitz, 2016a). Openness is also connected to universalism values, which include promoting peace and tolerance and seeing all people as equally deserving of justice and equality (Douglas, Bore, & Munro, 2016).
Further, research has linked openness to experience to broad intellectual skills and knowledge, and may tend to increase with age (Schretlen, van der Hulst, Pearlson, & Gordon, 2010). This indicates that openness to experience leads to gains in knowledge and skills, and naturally increases as a person ages and has more experiences to learn from.
Not only has openness been linked to knowledge and skills, it was also found to correlate with creativity, originality, and a tendency to explore their inner selves with a therapist or psychiatrist, and negatively related to conservative political attitudes (Soldz & Vaillant, 1999). Not only was openness found to correlate with many traits over time, it was also found to be extremely stable over time – one study explored trait stability over 45 years (Soldz & Vaillant, 1999), and found a relatively strong and significant correlation between the two times of measurement!
Concerning the other Big Five factors, openness to experience is weakly related to neuroticism and extroversion, and is mostly unrelated to agreeableness and conscientiousness (Ones, Viswesvaran, & Reiss, 1996).
Openness to experience is perhaps the trait that is least likely to change over time, and perhaps most likely to help an individual grow. Those high in openness to experience should capitalize on their advantage and explore the world, their selves, and their passions. These individuals make strong and creative leaders, and are the ones most likely to come up with the next big innovation.
This factor has been linked to achievement, conformity, and seeking out security, as well as relating negatively to placing a premium on stimulation and excitement (Roccas, Sagiv, Schwartz, & Knafo, 2002). Those high in conscientiousness are also likely to value order, duty, achievement, and self-discipline, and consciously practice deliberation and work towards increased competence (Roccas, Sagiv, Schwartz, & Knafo, 2002).
In light of these correlations, it’s not surprising that conscientiousness is also strongly related to post-training learning (Woods, Patterson, Koczwara, & Sofat, 2016), effective job performance (Barrick & Mount, 1991), and intrinsic and extrinsic career success (Judge, Higgins, Thoresen, & Barrick, 1999).The long-term study by Soldz and Vaillant (1999) found that conscientiousness was positively correlated with adjustment to life’s challenges and the maturity of one’s defensive responses, indicating that those high in conscientiousness are often well-prepared to tackle any obstacles that come their way. This factor is also negatively correlated with depression, smoking, substance abuse, and engagement in psychiatric treatment.
Conscientiousness was found to correlate somewhat negatively with neuroticism and somewhat positively with agreeableness, but had no discernible relation to the other factors (Ones, Viswesvaran, & Reiss, 1996).
From these results, it’s clear that those gifted with high conscientiousness have a distinct advantage over those who are not. Those with high conscientiousness should attempt to use their strengths to the best of their abilities, including organization, planning, perseverance, and tendency towards high achievement.
As long as the highly conscientious do not fall prey to exaggerated perfectionism, they are likely to achieve many of the traditional markers of success.
Those high in extroversion are likely to value achievement and stimulation, and unlikely to value tradition or conformity (Roccas, Sagiv, Schwartz, & Knafo, 2002). Extroverts are often assertive, active, and sociable, shunning self-denial in favor of excitement and pleasure.
Considering these findings, it follows that high extroversion is a strong predictor of leadership, and contributes to the success of managers and salespeople as well as the success of all job levels in training proficiency (Barrick & Mount, 1991). Over a lifetime, high extroversion correlates positively with a high income, conservative political attitudes, early life adjustment to challenges, and social relationships (Soldz & Vaillant, 1999).
The same long-term study also found that extroversion was fairly stable across the years, indicating that extroverts and introverts do not easily shift into the opposite state (Soldz & Vaillant, 1999).
Because of its ease of measurement and general stability over time, extroversion is an excellent predictor of effective functioning and general well-being (Ozer & Benet-Martinez, 2006), positive emotions (Verduyn & Brans, 2012), and overconfidence in task performance (Schaefer, Williams, Goodie, & Campbell, 2004).
When analyzed in relation to the other Big Five factors, extroversion correlated weakly and negatively with neuroticism and weakly positively related to openness to experience (Ones, Viswesvaran, & Reiss, 1996).
Those who score high in extroversion are likely to make friends easily and enjoy interacting with others, but they may want to pay extra attention to making well thought-out decisions and considering the needs and sensitivities of others.
Agreeable individuals tend to value benevolence, tradition, and conformity, while avoiding placing too much importance on power, achievement, or the pursuit of selfish pleasures (Roccas, Sagiv, Schwartz, & Knafo, 2002).
Agreeableness may be motivated by the desire to fulfill social obligations or follow established norms, or it may spring from a genuine concern for the welfare of others. Whatever the motivation, it is rarely accompanied by cruelty, ruthlessness, or selfishness (Roccas, Sagiv, Schwartz, & Knafo, 2002).
Those high in agreeableness are also more likely to have positive peer and family relationships, model gratitude and forgiveness, attain desired jobs, live long lives, experience relationship satisfaction, and volunteer in their community (Ozer & Benet-Martinez, 2006). Agreeableness affects so many life outcomes because it influences any arena in which interactions with others are important – this includes almost everything!
In the long-term, high agreeableness is related to strong social support and healthy midlife adjustment, but slightly negatively related to creativity (Soldz & Vaillant, 1999). Those who are friendly and endearing to others may find themselves without ample motivation to achieve traditional measure of success, instead focusing on family and friends.
Agreeableness correlates weakly with extroversion and is somewhat negatively related to neuroticism and somewhat positively related to conscientiousness (Ones, Viswesvaran, & Reiss, 1996).
Individuals high in agreeableness are likely to have many dear friends and a good relationship with family members, but there is as slight risk of consistently putting others ahead of themselves and missing out on opportunities for success, learning, and development. Those who are friendly and agreeable to others can leverage their strengths by turning to their social support network for help when needed, and finding fulfillment in positive engagement with their community.
Neuroticism has been found to relate negatively to self-esteem and general self-efficacy, as well as individual locus of control (Judge, Erez, Bono, & Thoresen, 2002). In fact, these four traits are so closely related that they may fall under one umbrella construct.
In addition to these clear associations, neuroticism has also been linked to poorer job performance and motivation, including goal setting and self-efficacy related motivation (Judge & Ilies, 2002). It is likely no surprise that emotional instability and vulnerability to stress and anxiety do not produce one’s best work.
The anxiety and self-consciousness component of neuroticism was also linked to more traditional values and negatively correlated with achievement values, while the hostility and impulsiveness component of neuroticism relate positively to hedonism (or seeking pleasure without regards to the long-term and with a certain disregard for right and wrong) and negatively to benevolence, tradition, and conformity (Roccas, Sagiv, Schwartz, & Knafo, 2002).
A stunningly long-term study from researchers Soldz and Vaillant showed that neuroticism, over a period of 45 years, was negatively correlated with smoking cessation, healthy adjustment to life, drug usage, alcohol abuse, and mental health issues (1999).
Neuroticism was found to correlate somewhat negatively with agreeableness and conscientiousness, in addition to a weak, negative relationship with extroversion and openness to experience (Ones, Viswevaran, & Reiss, 1996).
Overall, high neuroticism is related to added difficulties in life, including addiction, poor job performance, and unhealthy adjustment to life’s changes. Scoring high on neuroticism is not an immediate sentence to a miserable life, but those in this group would benefit from investing in improvements to their self-confidence, building resources to draw on in times of difficulty, and avoiding any substances with addictive properties.
Assessing the Big Five
There have been a few attempts to measure the five factors of the Big Five framework, but the most reliable and valid measurements come from the Big Five Inventory (BFI) and the Revised NEO Personality Inventory (NEO PI-R).
Big Five Inventory
This inventory was developed by Goldberg in 1993 to measure the five dimensions of the Big Five personality framework. It contains 44 items and measures each factor through its corresponding facets:
- Positive emotions
- Achievement striving
- Angry hostility
- Openness to experience
The responses to items concerning these facets are combined and summarized to produce a score on each factor. This inventory has been used extensively in psychology research and is still quite popular, although the NEO PI-R has also gained much attention in recent years.
The original NEO Personality Inventory (NEO PI) was created by personality researchers Paul Costa, Jr. and Robert McCrae in 1978. It was later revised to keep up with the changing times, once in 1990, once in 2005, and again in 2010. Initially, the NEO PI was named for the three main domains as the researchers understood them at the time: neuroticism, extroversion, and openness.
This scale is also based on the six facets of each factor, and includes 240 items rated on a 5-point scale. For a shorter scale, Costa and McCrae also offer the NEO Five-Factor Inventory (NEO FFI), which contains only 60 items and measures just the overall domains instead of all facets.
The NEO PI-R requires only a 6th grade reading level and can be self-administered (taken as an individual without a scoring professional).
Access to the NEO PI-R is kept on a stricter lockdown than the BFI, but you can learn more about the scale or purchase it for your own use here.
Take Home Message
This piece hopefully showed you that personality is a complex topic of research in psychology, with a long history of shifting philosophies and theories. While it’s easy to conceptualize personality on a day-to-day level, conducting valid scientific research on personality can be much more complex.
The Big Five can help you to learn more about your unique personality and help you decide where to focus your energy and attention.The first step to effectively leveraging your strengths is to learn what your strengths are. Whether you use the BFI, the NEO PI-R, the NEO FFI, or something else entirely, I hope you find a good scale to learn about where you fall on the OCEAN spectrums.
Thanks for reading, and as usual please leave us your thoughts in the comments section!
- APA. (2017). Personality. American Psychological Association. Retrieved from http://www.apa.org/topics/personality/
- Barrick, M. R., & Mount, M. K. (1991). The big five personality dimensions and job performance: a meta‐analysis. Personnel psychology, 44, 1-26.
- Boyce, C. J., Wood, A. M., & Powdthavee, N. (2013). Is personality fixed? Personality changes as much as “variable” economic factors and more strongly predicts changes to life satisfaction. Social Indicators Research, 111, 287-305. doi:10.1007/s11205-012-0006-z
- Douglas, H. E., Bore, M., & Munro, D. (2016). Openness and intellect: An analysis of the motivational constructs underlying two aspects of personality. Personality and Individual Differences, 99, 242-253. doi:10.1016/j.paid.2016.05.030
- John, O. P., & Srivastava, S. (1999). The Big-Five trait taxonomy: History, measurement, and theoretical perspectives. In L. A. Pervin & O. P. John (Eds.), Handbook of Personality: Theory and Research (Vol. 2, pp. 102-138). New York: Guilford Press.
- Judge, T. A., Higgins, C. A., Thoresen, C. J., & Barrick, M. R. (1999). The Big Five personality traits, general mental ability, and career success across the life span. Personnel Psychology, 52, 621-652.
- Judge, T. A., Erez, A., Bono, J. E., & Thoresen, C. J. (2002). Are measures of self-esteem, neuroticism, locus of control, and generalized self-efficacy indicators of a common core construct? Journal of Personality and Social Psychology, 83, 693-710. doi:10.1037/0022-35220.127.116.113
- Judge, T. A., & Ilies, R. (2002). Relationship of personality to performance motivation: A meta-analytic review. Journal of Applied Psychology, 87, 797-807. doi:10.1037/0021-9010.87.4.797
- Lebowitz, S. (2016a). The ‘Big 5’ personality traits could predict who will and won’t become a leader. Business Insider. Retrieved from http://www.businessinsider.com/big-five-personality-traits-predict-leadership-2016-12
- Lebowitz, S. (2016b). Scientists say your personality can be deconstructed into 5 basic traits. Business Insider. Retrieved from http://www.businessinsider.com/big-five-personality-traits-2016-12
- McLeod, S. (2007). Maslow’s hierarchy of needs. Simply Psychology. Retrieved from https://www.simplypsychology.org/maslow.html
- Ones, D. S., Viswesvaran, C., & Reiss, A. D. (1996). Role of social desirability in personality testing for personnel selection: The red herring. Journal of Applied Psychology, 81, 660-679. doi:10.1037/0021-9010.81.6.660
- Ozer, D. J., & Benet-Martinez, V. (2006). Personality and the prediction of consequential outcomes. Annual Review of Psychology, 57, 401-421. doi:10.1146/annurev.psych.57.102904.190127
- Revelle, W. (2013). Personality theory and research. Personality Project. Retrieved from https://www.personality-project.org/index.html
- Roccas, S., Sagiv, L., Schwartz, S. H., & Knafo, A. (2002). The Big Five personality factors and personal values. Personality and Social Psychology, 28, 789-801. doi:10.1177/0146167202289008
- Schaefer, P. S., Williams, C. C., Goodie, A. S., & Campbell, W. K. (2004). Overconfidence and the Big Five. Journal of Research in Personality, 38, 473-480. doi:10.1016/j.jrp.2003.09.010
- Schretlen, D. J., van der Hulst, E., Pearlson, G. D., & Gordon, B. (2010). A neuropsychological study of personality: Trait openness in relation to intelligence, fluency, and executive functioning. Journal of Clinical and Experimental Neuropsychology, 32, 1068-1073. doi:10.1080/13803391003689770
- Soldz, S., & Vaillant, G. E. (1999). The Big Five personality traits and the life course: A 45-year longitudinal study. Journal of Research in Personality, 33, 208-232. doi:10.1006/jrpe.1999.2243
- Twomey, S. (2010, January). Phineas Gage: Neuroscience’s most famous patient. Smithsonian. Retrieved from http://www.smithsonianmag.com/history/phineas-gage-neurosciences-most-famous-patient-11390067/
- Verduyn, P., & Brans, K. (2012). The relationship between extroversion, neuroticism, and aspects of trait affect. Personality and Individual Differences, 52, 664-669. doi:10.1016/j.paid.2011.12.017
- Woods, S. A., Patterson, F. C., Koczwara, A., & Sofat, J. A. (2016). The value of being a conscientious learner: Examining the effects of the big five personality traits on self-reported learning from training. Journal of Workplace Learning, 28, 424-434. doi:10.1108/JWL-10-2015-0073