Introduction to Personality

Defining Personality

Personality is the unique combination of patterns that influence behavior, thought, motivation, and emotion in a human being.

Learning Objectives

Trace the history of the field of personality psychology

Key Takeaways

Key Points

  • Personality is the combination of behavior, emotion, motivation, and thought patterns that define an individual. Personality psychology attempts to study similarities and differences in these patterns among different people and groups.
  • The study of personality began with Hippocrates’ theory of humorism, which argued that personality traits are based on four separate temperaments associated with four fluids (“ humors ”) of the body.
  • Modern personality psychology is heavily influenced by these early philosophical roots and attempts to identify which components—such as free will, heredity, or universality—are most influential in shaping human personality.
  • There are many approaches to the modern psychological study of personality, including the psychodynamic, neo-Freudian, learning, humanistic, biological, trait, and cultural perspectives.

Key Terms

  • humor: In an old usage, one of four fluids that were believed to control the health and mood of the human body.
  • psychodynamic: An approach to psychology that emphasizes the systematic study of the unconscious psychological forces that underlie human behavior, feelings, and emotions and how these might relate to early experience.

An individual’s personality is the combination of traits and patterns that influence their behavior, thought, motivation, and emotion. It drives individuals to consistently think, feel, and behave in specific ways; in essence, it is what makes each individual unique. Over time, these patterns strongly influence personal expectations, perceptions, values, and attitudes.

Personality psychology is the study of human personality and how it varies among individuals and populations. Personality has been studied for over 2000 years, beginning with Hippocrates in 370 BCE and spanning through modern theories such as the psychodynamic perspective and trait theory.

Early Philosophical Roots

The word “personality” originates from the Latin word persona, which means “mask.” Personality as a field of study began with Hippocrates, a physician in ancient Greece, who theorized that personality traits and human behaviors are based on four separate temperaments associated with four fluids of the body known as “humors”. This theory, known as humorism, proposed that an individual’s personality was the result of the balance of these humors (yellow bile, black bile, phlegm, and blood), which corresponded to four dispositions (grumpy, melancholy, calm, and cheer, respectively). While this theory is no longer held to be true, it paved the way for further discoveries and insight into human personality.

Interestingly, several words in the English language that describe personality traits are rooted in humorism: “bilious” means bad-tempered, which is rooted in humorists’ thought that yellow bile was associated with grumpiness; “melancholic” is from the Greek words for “black bile,” again rooted in humorists’ thought that black bile was associated with depression. Similarly, “phlegmatic” describes a calm personality and “sanguine” (from the Latin for “blood”) a cheerful or playful one.

A great deal of modern personality psychology is influenced by, and attempts to answer, the following five philosophical questions about what really determines personality:

  1. Freedom versus determinism: How much, if any, of an individual’s personality is under their conscious control?
  2. Heredity versus environment: Do internal (biological) or external (environmental) influences play a larger role in determining personality?
  3. Uniqueness versus universality: Are individuals generally more alike (similar to each other) or different (unique) in nature?
  4. Active versus reactive: Is human behavior passively shaped by environmental factors, or are humans more active in this role?
  5. Optimistic versus pessimistic: Are humans integral in the changing of their own personalities (for instance, can they learn and change through human interaction and intervention)?

Approaches to Studying Personality

Research into these five philosophical questions has branched into several different approaches to studying personality. The major theories include the psychodynamic, neo-Freudian, learning (or behaviorist), humanistic, biological, trait (or dispositional), and cultural perspectives.

  • Psychodynamic theory, originating with Sigmund Freud, posits that human behavior is the result of the interaction among various components of the mind (the id, ego, and superego) and that personality develops according to a series of psychosexual developmental stages.
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Sigmund Freud: Sigmund Freud advanced a psychodynamic view of human personality that implicated the id, ego, and superego as the main determinants of individual differences in personality.

  • Neo-Freudian theorists, such as Adler, Erikson, Jung, and Horney, expanded on Freud’s theories but focused more on the social environment and on the effects of culture on personality.
  • Learning theories, such as behaviorism, regard an individuals’ actions as ultimately being responses to external stimuli. Social learning theory believes that personality and behavior are determined by an individual’s cognition about the world around them.
  • Humanistic theory argues that an individual’s subjective free will is the most important determinant of behavior. Humanistic psychologists such as Abraham Maslow and Carl Rogers believed that people strive to become self-actualized—the “best version” of themselves.
  • Biological approaches focus on the role of genetics and the brain in shaping personality. Related to this, evolutionary theories explore how variation in individual personalities variance may be rooted in natural selection.
  • Trait theorists believe personality can be conceptualized as a set of common traits, or characteristic ways of behaving, that every individual exhibits to some degree. In this view, such personality traits are different from person to person but within an individual are stable over time and place.

With any of these theories, it is important to keep in mind that the culture in which we live is one of the most important environmental factors that shapes our personalities. Western ideas about personality are not necessarily applicable to other cultures, and there is evidence that the strength of personality traits varies across cultures.

Genetics, the Brain, and Personality

The biological perspective on personality emphasizes the influence of the brain and genetic factors on personality.

Learning Objectives

Discuss the relationship between genetics and personality development

Key Takeaways

Key Points

  • The biological perspective on personality focuses on why or how personality traits manifest through biology and investigates the links between personality, DNA, and processes in the brain.
  • In psychology, ” temperament ” refers to the personality tendencies that we show at birth (and that are therefore biologically determined). After birth, environmental factors and maturation interact with a child’s temperament to shape their personality.
  • The field of behavioral genetics focuses on the relationship between genes and behavior. Research from twin studies suggests that some aspects of our personalities are largely controlled by genetics.
  • The biological approach to personality has also identified areas and pathways within the brain, as well as various hormones and neurotransmitters, that are associated with the development of personality.
  • One of the first documented cases that demonstrated the link between personality and the brain was that of Phineas Gage, who underwent a drastic personality change after a brain injury.

Key Terms

  • temperament: A person’s normal manner of thinking, behaving, or reacting.
  • heritability: The proportion of difference among people that is attributed to genetics.

The Biological Perspective on Personality

The biological perspective on personality emphasizes the internal physiological and genetic factors that influence personality. It focuses on why or how personality traits manifest through biology and investigates the links between personality, DNA, and processes in the brain. This research can include the investigation of anatomical, chemical, or genetic influences and is primarily accomplished through correlating personality traits with scientific data from experimental methods such as brain imaging and molecular genetics.

Temperament

In psychology, “temperament” refers to the personality tendencies that we show at birth (and that are therefore biologically determined). For example, Thomas and Chess (1977) found that babies could be categorized into one of three temperaments: easy, difficult, or slow to warm up. After birth, environmental factors (such as family interactions) and maturation interact with a child’s temperament to shape their personality (Carter et al., 2008).

Research suggests that there are two dimensions of our temperament that are important parts of our adult personality: reactivity and self-regulation (Rothbart, Ahadi, & Evans, 2000). Reactivity refers to how we respond to new or challenging environmental stimuli; self-regulation refers to our ability to control that response (Rothbart & Derryberry, 1981; Rothbart, Sheese, Rueda, & Posner, 2011). For example, one person may immediately respond to a new stimulus with a high level of anxiety while another barely notices it.

Genetics and Personality

The field of behavioral genetics focuses on the relationship between genes and behavior and has given psychologists a glimpse of the link between genetics and personality. A large part of the evidence collected linking genetics and the environment to personality comes from twin studies, which compare levels of similarity in personality between genetically identical twins.

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Genetics: The expression of inherited genes plays a role in determining personality.

In the field of behavioral genetics, the Minnesota Study of Twins Reared Apart—a well-known study of the genetic basis for personality—conducted research with twins from 1979 to 1999. In studying 350 pairs of twins, including pairs of identical and fraternal twins reared together and apart, researchers found that identical twins, whether raised together or apart, have very similar personalities (Bouchard, 1994; Bouchard, Lykken, McGue, Segal, & Tellegen, 1990; Segal, 2012).

These findings suggest the heritability of some personality traits, implying that some aspects of our personalities are largely controlled by genetics. Multiple twin studies have found that identical twins do have higher correlations in personality traits than fraternal twins. While identical twins may have some similar personality traits, however, they still have distinct personalities, suggesting that genetics are not the only factor in determining personality. One study measuring genetic influence on twins in five different countries found that correlations for traits between identical twins were 0.50 (i.e., they had 50% of traits in common), while for fraternal twins were about 0.20 (i.e., they had 20% of traits in common). These findings suggest that heredity and environment interact to determine an individual’s personality.

It’s important to point out that traits are determined not by a single gene, but by a combination of many genes, and also by environmental factors that control whether certain genes are expressed. Many personality studies today investigate the activation and expression of genes and how they relate to personality. How DNA interacts with the environment determines what part of the DNA code is actually activated within an individual—in other words, which genes will be expressed. These small changes in individuals’ DNA help determine each person’s uniqueness—their distinct looks, abilities, brain functioning, and other characteristics that all work together to form a cohesive personality.

The Brain and Personality

The biological approach to personality has also identified areas and pathways within the brain that are associated with the development of personality. A number of theorists, such as Hans Eysenck, Gordon Allport, and Raymond Cattell, believe that personality traits can be traced back to brain structures and neural mechanisms, such as dopamine and seratonin pathways. Researchers using a biological perspective will seek to understand how hormones, neurotransmitters, and different areas of the brain all interact to affect personality.

Phineas Gage: A Case Study

One of the first documented cases that demonstrated the link between personality and the brain was that of Phineas Gage. In 1858, Gage was working as a blasting foreman for a railroad company. Due to a faulty blast, a railroad spike was blown through his head; miraculously, he survived the accident.

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Phineas Gage’s skull: The case of Phineas Gage was one of the first indicators of a biological basis for personality.

The spike pierced Gage’s frontal lobe, and Gage experienced many subsequent changes in aspects of personality that we now know are associated with this area of the brain. The changes in Gage’s personality after his brain injury spurred interest in the biological factors involved in personality and implicated the frontal lobe as an important area associated with higher-order personality functions.

Strengths of the Biological Perspective

One strength of the biological perspective is its strict adherence to scientific methodology. All factors are reduced to quantifiable variables that can be reliably measured by personality trait models and questionnaires. The personality measures are standardized across measurements, and these measures of personality are very compatible with statistical analyses, providing an easily administered and measurable definition of personality.

This method can also be deterministic, meaning that some factors are identified as causal—i.e., certain brain structures or patterns may be identified as causing certain psychological outcomes. Because of this, the biological perspective can be useful in identifying causes of and effective treatments for personality and mood disorders. For example, identifying seratonin imbalance as a cause of depression led to the development of selective seratonin reuptake inhibitors (SSRIs), which have been found to be an effective treatment for depression.

Limitations of the Biological Perspective

A limitation of this perspective is that it focuses almost exclusively on the nature side of the nature vs. nurture debate (the debate about whether genetics or environment are more influential in human development). Because of this exclusive focus, other factors that are integral to personality are not included. Hormones, neurotransmitters, and genetics are the key factors in this focus; the effects of environmental and social factors, however, are often overlooked. Twin studies have shown that heritable factors are not the only predictor of personality or even diseases such as schizophrenia; the biological perspective does not fully address non-heritable factors.

In addition, the correlational studies used for measuring normal personality traits are subjected to the same rules as normal correlational research: they cannot be used alone to establish causation. Just because two factors are shown to be related does not mean that one causes the other. For example, if you have data that show that as ice cream sales increase, the rate of drowning deaths also increases, you should not necessarily conclude that ice cream consumption causes drowning. In this case, more ice cream is sold during the hot summer months—the same time that people are more likely to go swimming. Therefore, the cause of the increases in both ice cream sales and drowning deaths is most likely the hot summer weather.

That said, properly designed experimental studies can help scientists determine cause-and-effect relationships in order to develop treatment options for people with personality disorders.

Influences of Culture and Gender on Personality

Both culture and gender are important factors that influence the development of personality.

Learning Objectives

Discuss the impact of culture and gender on personality development

Key Takeaways

Key Points

  • Personality is influenced by both biological and environmental factors; culture is one of the most important environmental factors that shapes personality.
  • Considering cultural influences on personality is important because Western ideas and theories are not necessarily applicable to other cultures. Research shows that the strength of personality traits varies greatly across cultures.
  • People who live in individualist cultures tend to value independence, competition, and personal achievement, while people from collectivist cultures tend to value social harmony, respectfulness, and group needs.
  • In much the same manner that cultural norms can influence personality and behavior, gender norms also emphasize different traits between different genders and thereby influence the development of personality.
  • In the U.S., aggression and assertiveness are emphasized as positive traits for males, while submissiveness and caretaking are emphasized for females.
  • There are three approaches that can be used to study personality in a cultural context: the cultural-comparative approach, the indigenous approach, and the combined approach, which incorporates elements of the first two approaches.

Key Terms

  • norms: That which is regarded as normal or typical; a rule that is enforced by members of a community.
  • trait: An identifying characteristic, habit or trend.
  • culture: The beliefs, values, behavior and material objects that constitute a people’s way of life.
  • gender: The socio-cultural phenomenon of the division of people into various categories according to their biological sex, with each having associated roles, clothing, stereotypes, etc.; those with male sex characteristics are perceived as “boys” and “men”, while those with female sex characteristics are perceived as “girls” and “women. “

A person’s culture is one of the most important environmental factors shaping their personality (Triandis & Suh, 2002). Personality psychologists are interested in understanding the role that culture plays in the development of personality. Research investigating the variations of personality traits across cultures suggests that there are both universal and culture-specific aspects that account for these variations.

Culture and Personality

The term culture refers to all of the beliefs, customs, ideas, behaviors, and traditions of a particular society that are passed through generations. Culture is transmitted to people through language as well as through the modeling of behavior, and it defines which traits and behaviors are considered important, desirable, or undesirable.

Within a culture there are norms and behavioral expectations. These cultural norms can dictate which personality traits are considered important. The researcher Gordon Allport considered culture to be an important influence on traits and defined common traits as those that are recognized within a culture. These traits may vary from culture to culture based on differing values, needs, and beliefs. Positive and negative traits can be determined by cultural expectations: what is considered a positive trait in one culture may be considered negative in another, thus resulting in different expressions of personality across cultures.

Considering cultural influences on personality is important because Western ideas and theories are not necessarily applicable to other cultures (Benet-Martinez & Oishi, 2008). There is a great deal of evidence that the strength of personality traits varies across cultures, and this is especially true when comparing individualist cultures (such as European, North American, and Australian cultures) and collectivist cultures (such as Asian, African, and South American cultures). People who live in individualist cultures tend to believe that independence, competition, and personal achievement are important. In contrast, people who live in collectivist cultures tend to value social harmony, respectfulness, and group needs over individual needs. These values influence personality in different but substantial ways; for example, Yang (2006) found that people in individualist cultures displayed more personally-oriented personality traits, whereas people in collectivist cultures displayed more socially-oriented personality traits.

Gender and Personality

In much the same manner that cultural norms can influence personality and behavior, gender norms (the behaviors that males and females are expected to conform to in a given society) can also influence personality by emphasizing different traits between different genders.

Ideas of appropriate behavior for each gender (masculine and feminine) vary among cultures and tend to change over time. For example, aggression and assertiveness have historically been emphasized as positive masculine personality traits in the United States. Meanwhile, submissiveness and caretaking have historically been held as ideal feminine traits. While many gender roles remain the same, others change over time. In 1938, for example, only 1 out of 5 Americans agreed that a married woman should earn money in industry and business. By 1996, however, 4 out of 5 Americans approved of women working in these fields. This type of attitude change has been accompanied by behavioral shifts that coincide with changes in trait expectations and shifts in personal identity for men and women.

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Influence of gender roles on personality expression: Gender roles can determine which traits are considered positive or desirable. These traits vary from culture to culture.

Approaches to Studying Personality in a Cultural Context

There are three approaches that can be used to study personality in a cultural context: the cultural-comparative approach, the indigenous approach, and the combined approach, which incorporates elements of the first two approaches.

  • The cultural-comparative approach seeks to test Western ideas about personality in other cultures to determine whether they can be generalized and if they have cultural validity (Cheung van de Vijver, & Leong, 2011). For example, researchers used the cultural-comparative approach to test the universality of McCrae and Costa’s Five Factor Model. They found applicability in numerous cultures around the world, with the Big Five traits being stable in many cultures (McCrae & Costa, 1997; McCrae et al., 2005).
  • The indigenous approach came about in reaction to the dominance of Western approaches to the study of personality in non-Western settings (Cheung et al., 2011). Because Western-based personality assessments cannot fully capture the personality constructs of other cultures, the indigenous model has led to the development of personality assessment instruments that are based on constructs relevant to the culture being studied (Cheung et al., 2011).
  • The third approach to cross-cultural studies of personality is the combined approach, which serves as a bridge between Western and indigenous psychology as a way of understanding both universal and cultural variations in personality (Cheung et al., 2011).