People are the deadliest invasive species in the history of the earth. People have the potential to kill every living thing and, in certain instances have already done so (e.g., passenger pigeon, western black rhinoceros, great auk) or are on their way to doing so (e.g., sea turtle, elephant, tiger, polar bear). Given their frightful potential and worldwide presence, it would be useful to know something about people. Personality psychology is the “go-to” discipline for understanding people; personality psychology is the only discipline whose primary focus is the nature of human nature. What does personality psychology tell us about human nature? The answer depends on whom you ask, or more precisely, to which personality theory you subscribe.
Keep reading to learn more about the history of personality theory, different theoretical approaches, and the role of personality in organizational and leadership performance.
History of Personality Theory
Modern personality psychology began in Vienna at the end of the 19th century, where an amazing flowering of human creativity brought revolutions in a wide variety of fields including architecture, music, physics, medicine, music, painting, literature, economics, and especially philosophy. Personality theory started as a psychodynamic version of psychiatry—mental illness was hypothesized to be a function of intrapsychic dynamics and the physical symptoms were secondary. The pioneers of this new way to conceptualize psychic troubles included Pierre Janet (who was French), Sigmund Freud, Carl Jung, Alfred Adler, Otto Rank, Erik Erikson, and others. Personality theory was a vibrant intellectual activity for 70 years but by the early 1970s, some prominent personality psychologists began to argue that personality theory was pointless, that only data mattered. In retrospect, Walter Mischel’s (1968) critique of personality psychology was more a symptom of the decline of personality theory than a cause—it reflected a changing culture rather than creating one.
The collapse of interest in personality theory created a hole in our ability to understand human affairs. This is because personality theory is unavoidable: everything we do depends on our assumptions about human nature. Even social psychology depends on (often untenable and unspecified) assumptions about human nature. We need to make these assumptions explicit for two reasons: (1) ideas have consequences—they drive everything we do; and (2) knowledge proceeds more efficiently from error than from confusion—bad ideas can be corrected, but unspecified assumptions lead to futility.
Types of Personality Theory
There are three major theories of personality, with subtypes within each. The first is the many versions of psychodynamic theory associated with clinical psychology. The second personality theory is trait theory, which concerns cataloguing dimension of individual differences. The third is interpersonal theory which largely concerns career coaching and development—i.e., applications to everyday life. In the following paragraphs, we briefly describe the history of each personality theory, identify its core assumptions, and evaluate the consequences of these assumptions.
Psychodynamic theory dominated personality psychology for 70 years and contains many valid insights. For example, early experience shapes later personality, much social behavior is unconsciously motivated, people are inherently irrational, and psychology can be used for human betterment. The three major assumptions of psychodynamic theory are: (1) everyone is somewhat neurotic; (2) the goal of life is to overcome one’s neurosis; and (3) the goal of personality assessment is to identify the sources of one’s neurosis. The problem with psychodynamic theory is the first assumption; everyone is not neurotic. Although most people have issues that bother them from time to time, to be neurotic is to be dysfunctional on a continuing basis and that is obviously not true for most people. In addition, as positive psychology points out, the absence of neurosis does not guarantee happiness or success. Lastly, diagnosing psychopathology is not the primary goal of personality assessment. Despite its compelling subject matter, psychodynamic theory pointed personality psychology in the wrong direction for 70 years. Positive psychology (Seligman, 2002) is a superficial, but natural, reaction to the excesses of psychodynamic theory.
Trait theory began in the 1930s as an academic exercise in classification and is largely defined by the writings of Gordon Allport (1937), Raymond Cattell (1943), Hans Eysenck (1947), and their students. The goal of trait theory is to classify the structure of personality; the units of analysis are “traits,” defined as (a) recurring behavioral tendencies; and (b) neuropsychic structures. The behavioral tendencies can be observed; the neuropsychic structures are inferred and believed to correspond to the behavioral tendencies. Trait theory makes three major assumptions: (1) everyone has traits; (2) the goal of life is to discover one’s traits; and (3) the goal of personality assessment is to measure traits. Despite the immense popularity of trait theory in modern psychology, it has limited utility as a personality theory for several reasons; here we will mention three. First, trait theory describes behavior in terms of traits, and then explains behavior in terms of traits (e.g., Mike Tyson is aggressive because he has a trait for aggressiveness); this is a tautology—as Walter Mischel (1968) pointed out long ago. Second, the search for the neuropsychic structures that explain the consistencies in behavior is a worthy project, but it is a project for neuro-scientists, not personality psychologists (it is also a project that has, thus far, yielded less than spectacular results). And third, the accepted taxonomy of traits, the Five-factor model (Wiggins, 1996), is based on ratings of school children in Hawaii (Digman, 1963) and Air Force enlisted men in Texas (Tupes & Crystal, 1961). Trait theory has in fact produced an common language for describing the reputation of others and identified a replicable structure underlying the trait terms. Nonetheless, it is not clear that the Five-Factor Model is (a) the most useful model for describing or predicting human behavior. In fact, there is compelling evidence showing that lower-order trait variables predict important outcomes better than the higher-order variables of the Five Factor Model (Brown & Sherman, 2014; Luminent, Bagby, Wagner, Taylor, & Parker, 1999; Paunonen & Ashton, 2001; Watson, 2001).
Interpersonal theory is based on the writings of William McDougall (1908), George Herbert Mead (1934), Henry Stack Sullivan (1953), George Kelly (1955), Timothy Leary (1957), and Jerry Wiggins (1996). The goal of interpersonal theory is to understand how people interact with others and how those interactions influence subsequent interactions. Interpersonal theory makes three major assumptions: (1) almost everything consequential in life occurs during social interaction, or as part of preparation for future social interaction, (2) the goal of life is to find and retain a productive place in one’s social network, and (3) the goal of personality assessment is to describe and predict how people will behave in social interactions. Interpersonal theory differs from trait and psychodynamic theory in three important ways. First, trait and psychodynamic theory assume that the way we think about ourselves drives our social interaction whereas interpersonal theory assumes that our social interaction drives how we think about ourselves (others teach us how to think about ourselves). Second, trait and psychodynamic theory define maturity as self-understanding whereas interpersonal theory defines maturity as the ability to interact productively with others (i.e., as social skill). Third, trait and psychodynamic theory ignore reputation, whereas interpersonal theory assumes that establishing and maintaining one’s reputation is crucial for a productive life.
Our perspective on personality theory, socioanalytic theory, integrates interpersonal theory with evolutionary psychology. Socioanalytic theory makes three major assumptions: (1) People always live in groups, and every group has a status hierarchy and a religion; (2) the goals of life concern getting along, getting ahead, and finding meaning; and (3) the goal of assessment is to predict individual differences in the ability to get along, get ahead, and find meaning. There are huge individual differences in peoples’ ability to get along, get ahead, and find meaning and there are huge payoffs in terms of fitness for being able to do so.
Evolutionary theory tells us that life is about competition. There is competition at the individual level (within groups) for status, power, and social acceptance; this competition is driven by sexual selection (Ridley, 1991). Then there is competition between groups for territory, market share, political dominance, and ultimately survival. Warfare drives human evolution at the group level (Turchin, 2006).
There are major individual differences in the ability of individuals to compete for status, and there are major differences in the abilities of groups to compete for survival (e.g., the Rohingya). Although psychologists focus almost exclusively on within-group competition, between group competition is more consequential. What is good for the individual may or may not be good for the group. Free riders—rent seekers who enjoy the benefits of group living without contributing to its maintenance and functioning—represent one such example (Cornes, 1986). On the other hand, what is good for the group is usually good for the members. Success at within-group competition is a function of social skill, which includes the ability to get along with others (to avoid expulsion from the group) and to get ahead (to maximize one’s resources). Success in between-group competition is a function of leadership.
Socioanalytic theory concerns predicting and explaining effectiveness of both individuals and groups.
Within-group competition takes place during social interaction—interaction is where the action is. In order to interact, people need an agenda for the interaction and they need roles to play. Overt agendas vary across interactions, but the covert agenda for most interactions concern negotiations for belonging and status. Three components of personality shape interactions: identity, reputation, and social skill. Our identities are the generic roles we take with us to each interaction; they determine the roles we play and how we play them. After every interaction there is an accounting process and people gain or lose a little bit of status; our reputations reflect the outcome of this accounting process. Reputations are inherently evaluative and indicate how well we are doing in the process of within-group competition. Social skill is what translates identity into reputation. Dysfunctional people choose maladaptive identities, create bad reputations for themselves, and lack the social skill needed to change the cycle. Competent people use their social skill to create reputations that match their identities and maximize their social and economic wellbeing.
Personality research has traditionally focused on studying the self and identity, but that search has not been productive. After 100 years, we still have no taxonomy of identities, no agreed upon methodology for measuring identity, and no useful generalizations about identity to report. Identity concerns the “you” that you know, and Freud would say (correctly) that the “you” that you know is hardly worth knowing—because you made it up. Your identity is the story you tell yourself about yourself, it is largely imagined and only loosely tied to reality.
In contrast, socioanalytic theory focuses on reputation—reputation is the “you” that others know. Reputation is easy to study by means of observer ratings. The Five-Factor Model of personality (Wiggins, 1976) is a robust taxonomy of reputation and, over the past 20 years, we have accumulated an abundance of findings regarding personality and many important life outcomes: marital satisfaction, health status, academic performance, substance abuse, driving records, income, social class, etc. (Roberts, et al., 2007; Ozer & Benet-Martinez, 2006). The best predictor of future behavior is past behavior, reputation is the summary of peoples’ past behavior, therefore reputation is the best data source we have regarding peoples’ future behavior. In our view, assessment should focus on reputation and not identity.
Let us clarify a key point here: although reputation (i.e., how others evaluate you) is the best predictor of future behavior, this does not mean that self-report assessments are useless. In our view, self-reports contain both identity claims (i.e., views of yourself that might not be true) and reputational information (certain identity claims are reliably associated with reputational outcomes). The reputational information is important, and the identity claims often muddy the water. Moreover, self-reports that are empirically tied to reputation (i.e., people with high scores on scale X are described by others as Y) are enormously useful. For example, the Hogan Personality Inventory (HPI: Hogan & Hogan, 2007) includes a scale called “Learning Approach.” People with high scores on this scale are described by others as smart, up-to-date and well-informed. Our emphasis on reputation does not imply that self-report tools are useless.
Nonetheless, we understand that identity research will not go away because people enjoy navel gazing and find discussions of identity fascinating. Although the academic study of identity has not been productive, there are three points about identity that are worth noting. First, Erikson (1963) argued that maturity depends on achieving a stable sense of identity. He defined identity in interpersonal terms—when behaving in ways that are most comfortable to yourself, you are most valuable to those people whom you most value—and we agree with him. Second, the Identity scale on Holland’s (1973) Self-Directed Search is the most valid scale on the inventory, based on external correlates. Third, the Identity HIC on the Hogan Personality Inventory is a highly valid component of the HPI based on external correlates. When identity is defined as having a sense of where your life is headed and what that means to others—not who you are but what you are trying to do—it is a meaningful and consequential concept.
Before ending this discussion of competition at the individual level, we should note how psychodynamic theory and trait theory define self-awareness and how we define self-awareness. Freud and Allport thought introspection and self-analysis leads to self-awareness, whereas we think performance analysis leads to self-awareness. The distinction is the same as that between Freud’s and Socrates’ definitions of self-awareness. The ancient Greeks valued self-knowledge: the inscription over the tomb of the Cumaean Sybill was “Know Thyself.” But for the Greeks, self-knowledge concerns understanding one’s performance capabilities and limitations. This is how we define self-awareness. We use personality assessment to create “strategic self- awareness” and enhance peoples’ ability to get along and get ahead.
Chimpanzee troops engage in genocide, ancient humans engaged in genocide, Native Americans practiced genocide—human history is a record of constant warfare. The Old Testament of the Bible is full of suggestions of the following variety: “When you capture a city, put to the sword all the men in it…utterly destroy them…save alive nothing that breatheth…As for the women and children, you may take them as plunder for yourselves” (Deuteronomy 2:10- 20). In the history of our species, if your tribe was overrun by another tribe, your opportunities for reproductive success ended abruptly. This is the reason we believe between-group competition trumps within-group competition. Success at within-group competition means nothing if you lose the between-group competition.
It seems clear that the success of armies, athletic teams, business enterprises, universities, religious organizations—any collective activity—depends on the leadership of that collectivity. But from WWII until the early 1980s, academic psychology thought individual differences in the talent for leadership was a myth, that leadership was situational, and if you were successful in a leadership role, you were just lucky. As of today, there is still no consensus regarding the characteristics of competent leaders. In our view, the academic study of leadership suffers from five major problems: (1) the wrong definition of leadership; (2) no attention to the consequences of leadership; (3) no attention to the subordinates’ view of leadership; (4) no attention to derailment; and (5) no attention to personality. Progress is being made, but these issues remain salient. We now take them up in turn.
Most research defines leadership in terms of the people at the top of organizations. But who gets to the top of large, hierarchical, bureaucratic, male-dominated organizations? People with good political skills who win the within-group competition for status. A meta-analysis of leader personality (i.e., the personality of people in leadership roles) indicates that leaders tend to score low on Neuroticism and high on Extraversion, Openness, and Conscientiousness (Judge, Bono, Ilies, & Gerhardt, 2002). Clearly these individuals have talent for acquiring status. But, do they have any talent for leading their groups to success?
An alternative view of leadership, and one that we prefer, is to define leadership from the perspective of group effectiveness. For the most part, people are biologically wired to behave selfishly (Dawkins, 1976). However, people are also capable of altruism when altruism (a) serves their long-term self-interest or (b) promotes the interests of those sharing their genetic material (Fletcher & Doebeli, 2008; Hamilton, 1964a, b; Nowak, Tarnita, & Wilson, 2010; Trivers, 1971). Further, the history of human warfare and modern team sports indicates that cohesive and coordinated groups outperform disorganized groups. Thus, in our view, the primary goal of leadership is to persuade people to temporarily set aside their selfish desires for the good of the group. In this view, leadership should be evaluated on the basis of the group’s performance, not on the basis of one’s ability to gain leadership positions. Politicians are skilled at gaining leadership positions; effective leaders are skilled at building and maintaining high-performing teams.
When it comes to competition between groups, leadership plays a critical role (Hanson, 2001; Hogan & Kaiser, 2005; Kaiser, Hogan, & Craig, 2008). Obvious examples include:
- The recent and sustained success of the New England Patriots football team compared to the recent and sustained failure of the Cleveland Browns football team
- The success of the Union Army over the Army of Northern Virginia in the US civil war
- The sustained success of Royal Dutch Shell Petroleum company compared to the colossal failure of Enron
There are many such lists of competing organizations outperforming one another. Researchers are finally beginning to understand that the leadership of an organization has consequences for the members of the organizations. For example, economists (who are interested in the financial consequences of personality) estimate that CEOs account for between 17% to 30% of the variance in firm financial performance (Hambrick & Mason, 1984; Hambrick & Quigley, 2014; Mackey, 2008; Quigley & Graffin, 2016; Quigley & Hambrick, 2014). CEO personality is more important for firm performance than any other factor except the industry sector in which the firm competes.
If leadership is about building teams, then it is important to know how the teams react to the leadership to which they are exposed. The team members are the consumers of leadership and will react accordingly. Employee engagement can be easily assessed using survey methodology. Over the past 20 years, overwhelming evidence shows that employee engagement predicts every significant organizational outcome, positive or negative, including absenteeism, turnover, productivity, quality, and customer service ratings. The lower the engagement levels, the worse the outcomes, the higher the engagement levels the better the outcomes (Harter, Schmidt, & Hayes, 2002). But most importantly for this discussion, the personalities of the managers create the engagement levels of their staff. And, on average, what do those personalities look like? The news is not encouraging.
Consider the following from various lines of survey research. A recent survey of the UK public indicated that 22% of people hate their boss, 52% of people name their boss as their main cause of dissatisfaction, 20% would forgo a pay raise if someone would fire their boss, and an astonishing 12% of respondents admit to having imagined killing their boss (Whitfield, 2018). In a similar US survey, 65% of Americans say they would prefer getting rid of their boss to receiving a pay raise (Casserly, 2012). On this basis, we estimate that 65% to 75% of managers in the U. S. economy, public and private sector, are incompetent and alienate their subordinates.
In an important piece of unpublished research, V. Jon Bentz, Vice President for Human Resources at Sears during the 1970s, hired hundreds of new managers using an assessment center (Bentz, 1985). All newly hired managers were bright and personally attractive. Bentz was a meticulous record keeper; he found that 65% of these new managers failed (the number is important). He found that the reasons for their failure nicely fit into 11 categories which, upon closer examination, nicely paralleled the DSM III, axis 2 personality disorders. Thus, managerial failure seems unrelated to intellectual competence (e.g., IQ), and directly related to interpersonal competence. Personality is the core of interpersonal incompetence and thus the core of managerial failure.
There is little agreement in the academic research regarding effective leadership (i.e., the characteristics of people who can build and maintain high performing teams), though three lines of research converge to define effective leadership: (1) Implicit leadership theory (Kouzes and Posner, 2008); (2) Research on emergent vs. effective managers (Luthans, Hodgetts, & Rosenkrantz, 1988); and (3) Research on organizational effectiveness (Collins, 2001).
Implicit leadership theory. Implicit leadership theory is based on the assumption that, because leadership has been such an important factor in human history, people have a rough intuitive sense of the characteristics of good leaders. Kouzes and Posner devised a simple but effective way to summarize those intuitions: ask people to describe the best and the worst bosses they ever knew. The results, aggregated over millions of responses, suggest that people believe good leaders share four characteristics. First, effective leaders have integrity—they keep their word, they do not play favorites, they do not self-deal, and they live up to their obligations. Because lying, along with money, is the mother’s milk of politics, many politicians quickly lose their credibility as leaders. Second, team captains are usually the best players on the teams, professional sports coaches are usually former athletes, etc. Consequently, effective leaders need to have real expertise in whatever business a team’s major focus might be. Newly minted officers in the military have credibility issues because they lack deep knowledge of operations at the daily level, and experienced enlisted personnel tend not to take them seriously as a result.
Subordinates are more likely to have faith in leaders who know something about the business that they are leading. Third, the fate of any organization depends on the outcomes of all the decisions that are made on a daily basis. Good leaders need to be able to make sound, defensible decisions quickly and on the basis of limited information. Making good decisions also involves changing bad decisions when it becomes apparent that they are wrong—good leaders can admit their mistakes. Finally, good leaders project a vision and create persuasive stories about why what the team or group is doing is important. In summary, implicit leadership theory offers a great deal of evidence to indicate that effective leaders are perceived as having integrity, competence, good judgment, and vision.
Emergent versus Effective Leaders. Luthans and his colleagues (1988) gathered comprehensive data on 457 managers from several organizations over a four-year period. At the end of the study, they collected performance data on the managers. They found two groups of high performers: (1) those who advanced rapidly in the organization; and (2) those whose teams performed well. There was a 10% overlap in the groups (r = .30). The important finding concerned how the two groups spent their time. The people who advanced rapidly spent their time networking. The people whose teams performed well spent their time working with their teams. These two types of managers map directly on to the concepts of leadership emergence and effectiveness previously discussed. Emergent managers are regularly identified as high potential employees, while effective managers are overlooked because they do not stand out and play organizational politics. It is the is process of promoting emergent managers, and overlooking effective managers, that creates the high rate of managerial failure in corporate affairs.
Organizational Effectiveness. Collins and his colleagues (2001) studied the Fortune 1000 companies to identify companies with 15 years of mediocre financial performance and then 15 years of superior performance. He found 11 companies that fit this profile. For comparison purposes, he also identified 11 companies, in the same industry, who showed only mediocre performance across the same time period. Analyses revealed that the cause of the turnarounds was the arrival of new CEOs. But the crucial finding is not that CEOs matter, but rather what kind of CEO matters. And the answer is the CEO personality is what mattered. In particular, the 11 successful CEOs were: (1) fiercely competitive and hard-working; and (2) humble, modest, and understated. That is, this group of high-performing CEOs were, in Luthan’s (1988) terms, effective not emergent. Thus, the available evidence indicates that effective leaders are (a) trustworthy, (b) competent, (c) have good judgment, (d) project an appealing vision, and (e) blend fierce ambition with personal humility. Thus, leadership effectiveness is a function of personality.
Last Thoughts on Personality Psychology
Personality psychology began as an applied activity (Stagner, 1937) and at its best it remains an applied activity directed at solving real problems for real people. The key problems for personality research concern predicting and explaining the outcomes of within and between group competition. Career success (the result of within-group competition) and organizational effectiveness (the result of between-group competition) are the most crucial issues in life. How can personality psychology help people have more successful careers? Mostly by creating strategic self-awareness and eliminating self-defeating behavior. How can personality psychology help organizations become more effective? Mostly by helping them hire effective leaders.
Want to learn more about personality tests? Check out The Ultimate Guide to Personality Tests
*This article was written by Dr. Robert Hogan and Dr. Ryne Sherman for a special issue of Personality and Individual Differences.
Allport, G.W. (1937). Personality: A Psychological Interpretation. New York: Holt, Rinehart, & Winston.
Bentz, V. J. (1985). A view of the top: a thirty-year perspective of research devoted to the discovery, description and prediction of executive behavior. Invited address, Division 14, 93rd Annual Convention, American Psychological Association, Los Angeles, CA.
Brown, N. A., & Sherman, R. A. (2014). Predicting interpersonal behavior using the inventory of individual differences in the lexicon (IIDL). Journal of Research in Personality, 51, 23-28.
Casserly, M. (October, 2017). Majority of Americans would rather fire their boss than get a raise. Forbes. Retrieved from: https://www.forbes.com/sites/meghancasserly/2012/10/17/majority- of-americans-would-rather-fire-their-boss-than-get-a-raise/#37f6c2ae6610
Cattell, R. B. (1943). The description of personality. Journal of Abnormal and Social Psychology, 38, 476-506.
Collins, J. (2001). Good to Great. New York: HarperCollins.
Cornes, R. (1986). The Theories of Externalities, Public Goods, and Club Goods. Cambridge, UK: Cambridge University Press.
Dawkins, R. (1976). The Selfish Gene. Oxford: Oxford University Press.
Digman, J. M. (1963). Principal dimensions of child personality as inferred from teachers’ judgments. Child Development 34, 43-60.
Erikson, E. (1963). Childhood and society. New York: Norton.
Eysenck, H. J. (1947). Dimensions of Personality. London: Metheun.
Fletcher, J. A., & Doebeli, M. (2008). A simple and general explantion for the eovluton of altruism. Proceedings of the Royal Society B: Biological Sciences, 276(1654).
Hambrick, D. C., & Mason, P. A. (1984). Upper Echelons: The organization as a reflection of its top managers. Academy of Management Review, 9(2), 193-206.
Hambrick, D. C., & Quigley, T. J. (2014). Toward a more accurate contextualization of the CEO effect on firm performance. Strategic Management Journal, 35, 473-491.
Hamilton, W. D. (1964a). The genetical evolution of social behaviour. Journal of Theoretical Biology, 7(1), 1-16.
Hamilton, W. D. (1964b). The genetical evolution of social behaviour. Journal of Theoretical Biology, 7(1), 17-52.
Hanson, V. D. (2001). Why the West has Won. London, UK: Faber and Faber.
Harter, J.K., Schmidt, F.L. & Hayes, T.L. (2002). Business-unit-level-relationships between employee satisfaction, employee engagement, and business outcomes: a meta-analysis. Journal of Applied Psychology, 87, 268-279.
Hogan, R. & Hogan, J. (2007) Hogan Personality Inventory, 3rd Edition.
Tulsa: Hogan Press. Hogan, R., & Kaiser, R. B. (2005). What we know about leadership. Review of General Psychology, 9(2), 169-180.
Judge, T.A., Bono, J.E., Ilies, R., & Gerhardt, M.W. (2002). Personality and leadership. Journal of Applied Psychology, 87, 765-780.
Kaiser, R. B., Hogan, R., & Craig, S. B. (2008). Leadership and the fate of organizations. American Psychologist, 63(2), 96-110.
Kelly, G. A. (1955). The Psychology of Personal Constructs. New York: Norton.
Leary, T. (1957). Interpersonal Diagnosis of Personality: A Functional Theory and Methodology for Personality Evaluation. Eugene, OR: John Wiley & Sons.
Luminent, O., Bagby, R. M., Wagner, H. L., Taylor, G. J., & Parker, J. D. A. (1999). Relation between alexithymia and the five-factor model of personality: A facet-level analysis. Journal of Personality Assessment, 73, 345-358.
Luthans, F., Hodgetts, R.M., & Rosenkrantz, S.A. (1988). Real managers. Cambridge, MA: Ballinger.
Mackey, A. (2008). The effect of CEOs on firm performance. Strategic Management Journal, 29, 1357-1367.
McDougall, W. (1908). Introduction to Social Psychology. London: Methuen & Co.
Mead, G. H. (1934). Mind, Self, and Society. Chicago, IL: University of Chicago Press.
Mischel, W. (1968). Personality and Assessment. Mahwah, NJ: Lawrence Erlbaum Associates.
Nowak, M., Tarnita, C., E., & Wilson, E. O. (2010). The evolution of eusociality. Nature, 466, 1057-1062.
Ozer, D. J., & Benet-Martinez, V. (2006). Personality and the prediction of consequential outcomes. Annual Review of Psychology, 57, 401-421.
Paunonen, S. V., & Ashton, M. C. (2001). Big five factors and facets and the prediction of behavior. Journal of Personality and Social Psychology, 81(3), 524-539.
Quigley, T. J., & Graffin, S. D. (2017). Reaffirming the CEO effect is significant and much larger than change: A comment on Fitza (2014). Strategic Management Journal, 38, 793-801.
Quigley, T. J., & Hambrick, D. C. (2014). Has the “CEO effect” increased in recent decades? A new explanation for the great rise in America’s attention to corporate leaders. Strategic Management Journal, 36, 821-830.
Ridley, M. (1991). The Red Queen: Sex and the Evolution of Human Nature. New York: HarperCollins.
Roberts, B. W., Kuncel, N. R., Shiner, R., Caspi, A., & Goldberg, L. R. (2007). The power of personality: The comparative validity of personality traits, socioeconomic status, and cognitive ability for predicting important life outcomes. Perspectives on Psychological Science, 2(4), 313-345.
Seligman, M.E.P. (2002). Authentic Happiness: Using the New Positive Psychology to Realize Your Potential for Lasting Fulfillment. New York: The Free Press.
Stagner, R. (1937). Psychology of personality. New York: McGraw-Hill.
Sullivan, H. S. (1953). The Interpersonal Theory of Psychiatry. New York: Norton.
Tupes, E. C., and Christal, R. E. (1961). Recurrent personality factors based on trait ratings (USAF ASD Tech. Rep. No. 61-97); Lackland Air Force Base, TX: U. S Air Force.
Turchin, P. (2006). War and peace and war. New York: Penguin.
Trivers, R. L. (1971). The evolution of reciprocal altruism. Quarterly Review of Biology, 46, 35-57.
Watson, D. (2001). Procrastination and the five-factor model: A face level analysis. Personality and Individual Differences, 30, 149-158.
Whitfiled, H. (2018). Horrible bosses: Have you ever imagined killing your boss? Focus. https://www.expertmarket.co.uk/focus/horrible-bosses
Wiggins, J. S. (1996). The five-factor Model of personality: Theoretical Perspectives. New York: Guilford.