Theories of Personality Psychology

Characteristics of personality

Verywell / Bailey Mariner

Theories of personality seek to explain how personality forms, how it changes, and the impact it has on behavior. In order to understand the personality theories in psychology, it is essential to understand some of the basics about personality.

What exactly is personality? Where does it come from? Does it change as we grow older? These are the sorts of questions that have long held the fascination of psychologists and which have inspired a number of different theories of personality. 

Major Theories of Personality

Personality psychology is the focus of some of the best-known psychology theories by a number of famous thinkers including Sigmund Freud and Erik Erikson. Some of these theories attempt to tackle a specific area of personality while others attempt to explain personality much more broadly.

Five of the main theories of personality are biological theories, behavioral theories, psychodynamic theories, humanist theories, and trait theories.

Biological Theories of Personality

Biological approaches suggest that genetics are responsible for personality. In the classic nature versus nurture debate, the biological theories of personality side with nature.

Research on heritability suggests that there is a link between genetics and personality traits. Twin studies are often used to investigate which traits might be linked to genetics versus those that might be linked to environmental variables. For example, researchers might look at differences and similarities in the personalities of twins reared together versus those who are raised apart.

One of the best known biological theorists was Hans Eysenck, who linked aspects of personality to biological processes.

Eysenck argued that personality is influenced by the stress hormone cortisol. According to his theory, introverts have high cortical arousal and avoid stimulation, while extroverts had low cortical arousal and crave stimulation.

Behavioral Theories of Personality

Behavioral theorists include B. F. Skinner and John B. Watson. Behavioral theories suggest that personality is a result of interaction between the individual and the environment. Behavioral theorists study observable and measurable behaviors, rejecting theories that take internal thoughts, moods, and feelings play a part as these cannot be measured.

According to behavioral theorists, conditioning (predictable behavioral responses) occurs through interactions with our environment which ultimately shapes our personalities.

Psychodynamic Theories of Personality

Psychodynamic theories of personality are heavily influenced by the work of Sigmund Freud and emphasize the influence of the unconscious mind and childhood experiences on personality. Psychodynamic theories include Sigmund Freud's psychosexual stage theory and Erik Erikson's stages of psychosocial development.

Freud believed the three components of personality were the id, ego, and superego. The id is responsible for needs and urges, while the superego regulates ideals and morals. The ego, in turn, moderates the demands of the id, superego, and reality.

Freud suggested that children progress through a series of stages in which the id's energy is focused on different erogenous zones.

Erikson also believed that personality progressed through a series of stages, with certain conflicts arising at each stage. Success in any stage depends on successfully overcoming these conflicts.

Humanist Theories of Personality

Humanist theories emphasize the importance of free will and individual experience in the development of personality. Humanist theorists include Carl Rogers and Abraham Maslow.

Humanist theorists promote the concept of self-actualization, which is the innate need for personal growth and the ways that personal growth motivates behavior.

Trait Theories of Personality

The trait theory approach is one of the most prominent areas in personality psychology. According to these theories, personality is made up of a number of broad traits. A trait is a relatively stable characteristic that causes an individual to behave in certain ways. It is essentially the psychological "blueprint" that informs behavioral patterns.

Some of the best-known trait theories include Eysenck's three-dimension theory and the five-factor theory of personality.

Eysenck utilized personality questionnaires to collect data from participants and then employed a statistical technique known as factor analysis to analyze the results. Eysenck concluded that there were three major dimensions of personality: extroversion, neuroticism, and psychoticism.

Eysenck believed that these dimensions then combine in different ways to form an individual's unique personality. Later, Eysenck added the third dimension known as psychoticism, which related to things such as aggression, empathy, and sociability.

Later researchers suggested that there are five broad dimensions that make up a person's personality, often referred to as the Big 5 theory of personality.

The Big 5 theory suggests that all personalities can be characterized by five major personality dimensions: openness, conscientiousness, extroversion, agreeableness, and neuroticism, collectively referred to by the acronym OCEAN.

Defining Personality

While personality is something that we talk about all the time ("He has such a great personality!" or "Her personality is perfect for this job!"), you might be surprised to learn that psychologists do not necessarily agree on a single definition of what exactly constitutes personality.

Personality is broadly described as the characteristic patterns of thoughts, feelings, and behaviors that make a person unique. In plain English, it is what makes you you.

Researchers have found while some external factors can influence how certain traits are expressed, personality originates within the individual. While a few aspects of personality may change as we grow older, personality also tends to remain fairly consistent throughout life.

Because personality plays such an important role in human behavior, an entire branch of psychology is devoted to the study of this fascinating topic. Personality psychologists are interested in the unique characteristics of individuals, as well as similarities among groups of people.

Characteristics of Personality

In order to understand the psychology of personality, it is important to learn some of the key characteristics of how personality works.

  • Personality is organized and consistent. We tend to express certain aspects of our personality in different situations and our responses are generally stable. 
  • Although personality is generally stable, it can be influenced by the environment. For example, while your personality might lead you to be shy in social situations, an emergency might lead you to take on a more outspoken and take-charge approach.
  • Personality causes behaviors to happen. You react to the people and objects in your environment based on your personality. From your personal preferences to your choice of a career, every aspect of your life is affected by your personality.

Investigating Theories of Personality

Now that you know a bit more about the basics of personality, it's time to take a closer look at how scientists actually study human personality. There are different techniques that are used in the study of personality. Each technique has its own strengths and weaknesses.

Experimental Methods

Experimental methods are those in which the researcher controls and manipulates the variables of interest and takes measures of the results. This is the most scientific form of research, but experimental research can be difficult when studying aspects of personality such as motivations, emotions, and drives.

These ideas are internal, abstract, and can be difficult to measure. The experimental method allows researchers to look at cause-and-effect relationships between different variables of interest.

Case Studies

Case studies and self-report methods involve the in-depth analysis of an individual as well as information provided by the individual. Case studies rely heavily on the interpretations of the observer, while self-report methods depend on the memory of the individual of interest.

Because of this, these methods tend to be highly subjective and it is difficult to generalize the findings to a larger population.

Clinical Research

Clinical research relies upon information gathered from clinical patients over the course of treatment. Many personality theories are based on this type of research, but because the research subjects are unique and exhibit abnormal behavior, this research tends to be highly subjective and difficult to generalize.

Key Terms in Theories of Personality

In addition to understanding some of the major theories of personality psychology, it is important to know more about some of the key terms and concepts that are central to these theories.

Classical Conditioning

Classical conditioning is a behavioral training technique that begins with a naturally occurring stimulus eliciting an automatic response. Then, a previously neutral stimulus is paired with the naturally occurring stimulus.

Eventually, the previously neutral stimulus comes to evoke the response without the presence of the naturally occurring stimulus. The two elements are then known as the conditioned stimulus and the conditioned response.

Operant Conditioning

Operant conditioning is a behavior training technique in which reinforcements or punishments are used to influence behavior. An association is made between a behavior and a consequence for that behavior.


In Freud’s psychoanalytic theory of personality, the unconscious mind is a reservoir of feelings, thoughts, urges, and memories that are outside of our conscious awareness. Most of the contents of the unconscious are unacceptable or unpleasant, such as feelings of pain, anxiety, or conflict.

According to Freud, the unconscious mind continues to influence our behavior and experiences, even though we are unaware of these underlying influences.


According to Freud’s psychoanalytic theory of personality, the id is the personality component made up of unconscious psychic energy that works to satisfy basic urges, needs, and desires. The id operates based on the pleasure principle, which demands immediate gratification of needs.


According to Freud, the ego is the largely unconscious part of the personality that mediates the demands of the id, the superego, and reality. The ego prevents us from acting on our basic urges (created by the id) but also works to achieve a balance with our moral and idealistic standards (created by the superego).


The superego is the component of personality composed of our internalized ideals that we have acquired from our parents and from society. The superego works to suppress the urges of the id and tries to make the ego behave morally, rather than realistically.

Thinkers Behind Theories of Personality

Some of the most famous figures in the history of psychology left a lasting mark on the field of personality. In order to better understand the different theories of personality, it can be helpful to learn more about the lives, theories, and contributions to the psychology of these eminent psychologists.

Sigmund Freud

Sigmund Freud (1856-1939) was the founder of psychoanalytic theory. His theories emphasized the importance of the unconscious mind, childhood experiences, dreams, and symbolism. His theory of psychosexual development suggested that children progress through a series of stages during which libidinal energy is focused on different regions of the body.

His ideas are what as known as grand theories because they seek to explain virtually every aspect of human behavior. Some of Freud's ideas are considered outdated by modern psychologists, but he had a major influence on the course of psychology, and some concepts, such as the usefulness of talk therapy and the importance of the unconscious, are enduring.

Erik Erikson

Erik Erikson (1902-1994) was an ego psychologist trained by Anna Freud. His theory of psychosocial stages describes how personality develops throughout the lifespan. Like Freud, some aspects of Erikson's theory are considered outdated by contemporary researchers, but his eight-stage theory of development remains popular and influential.

B. F. Skinner

B. F. Skinner (1904-1990) was a behaviorist best known for his research on operant conditioning and the discovery of schedules of reinforcement. Schedules of reinforcement influence how quickly a behavior is acquired and the strength of response.

The schedules described by Skinner are fixed-ratio schedules, fixed-variable schedules, variable-ratio schedules, and variable-interval schedules.

Sandra Bem

Sandra Bem (1944-2014) had an important influence in psychology and on our understanding of sex roles, gender, and sexuality. She developed her gender schema theory to explain how society and culture transmit ideas about sex and gender. Gender schemas, Bem suggested, were formed by things such as parenting, school, mass media, and other cultural influences. 

Abraham Maslow

Abraham Maslow (1908-1970) was a humanist psychologist who developed the well-known hierarchy of needs. The hierarchy includes physiological needs, safety and security needs, love and affection needs, self-esteem needs, and self-actualizing needs.

Carl Rogers

Carl Rogers (1902-1987) was a humanist psychologist who believed that all people have an actualizing tendency - a drive to fulfill the individual potential that motivates behavior. Rogers called healthy individuals fully-functioning, describing these individuals as those who are open to experience, live in the moment, trust their own judgment, feel free, and are creative.

A Word From Verywell

Personality makes us who we are, so it is no wonder why it has been the source of such fascination in both science and in daily life. The various theories of personality that have been proposed by different psychologists have helped us gain a deeper and richer understanding of what makes each person unique.

By learning more about these theories, you can better understand how researchers have come to know the psychology of personality as well as consider questions that future research might explore.

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Additional Reading

By Kendra Cherry
Kendra Cherry, MS, is the author of the "Everything Psychology Book (2nd Edition)" and has written thousands of articles on diverse psychology topics. Kendra holds a Master of Science degree in education from Boise State University with a primary research interest in educational psychology and a Bachelor of Science in psychology from Idaho State University with additional coursework in substance use and case management.