Why Your Personality Is Not Set in Stone: The Surprising Origins of Who You Are

Discover the surprising origins of personality! From genetics to upbringing and life experiences, learn how different factors shape who we are in this in-depth exploration.

Personality is a complex and multifaceted construct that refers to the unique set of traits, characteristics, and behaviors that define an individual. While some researchers believe that personality is largely determined by genetics (nature), others argue that environmental factors, such as upbringing and life experiences, play a significant role (nurture). In this article, we will explore the different theories of personality development and try to understand the origins of personality.

Biological Theories of Personality

One of the earliest theories of personality development is the biological theory, which posits that an individual’s personality is largely determined by genetics. According to this theory, each person is born with a set of innate personality traits that are passed down through the generations. For example, some people may be naturally outgoing and sociable, while others may be introverted and prefer to spend time alone. 

Furthermore, twin and adoption studies have shown that certain personality traits, such as extraversion, neuroticism, and conscientiousness, are highly heritable, with genetics accounting for anywhere between 40% and 60% of the variance in these traits (Jang, Livesley, & Vernon, 1996).

Another key assumption of biological theories of personality is that the brain and nervous system are central to the expression of personality. For example, research has shown that certain brain structures, such as the amygdala and prefrontal cortex, are involved in regulating emotional responses and decision-making, and may therefore influence personality traits such as emotional stability and impulsivity.

Recent research has identified specific genes that may be associated with certain personality traits, such as the gene for dopamine receptor D4 (DRD4), which has been linked to novelty-seeking behavior (DeYoung, Hirsh, Shane, Papademetris, Rajeevan, & Gray, 2010). While genetics undoubtedly play a role in shaping personality, it is important to note that environmental factors can also influence how genes are expressed.

We are who we are largely because of the genes we inherited from our parents.

Environmental Theories of Personality

In contrast to biological theories, environmental theories of personality suggest that personality is shaped primarily by environmental factors such as upbringing, life experiences, and cultural background. The most prominent of these theories is Sigmund Freud’s psychodynamic theory, which emphasizes the role of early childhood experiences in shaping personality (Freud, 1915).

According to this theory, a person’s personality is largely determined by their experiences during the first few years of life, particularly their relationship with their parents. For example, a child who receives consistent love and attention from their parents is more likely to develop a secure attachment style and a healthy sense of self-esteem, while a child who experiences neglect or abuse may develop an insecure attachment style and low self-esteem (McLeod, 2018).

Other environmental theories of personality include the social learning theory, which suggests that individuals learn personality traits through observation and modeling of others, and the humanistic theory, which emphasizes the role of personal growth and self-actualization in shaping personality.

Personality is not something that comes ready-made, but something that develops from social experience.

Interactionist Theories of Personality

While biological and environmental theories offer different perspectives on the origins of personality, interactionist theories suggest that both genetic and environmental factors interact to shape an individual’s personality. These theories suggest that while genetics may provide a foundation for certain personality traits, environmental factors such as parenting, peer relationships, and life experiences can influence how these traits are expressed.

One of the key proponents of interactionist theory was psychologist Albert Bandura. His theory of social learning proposed that people learn by observing and imitating the behavior of others. Bandura argued that personality is shaped not only by environmental factors, but also by a person’s own experiences and their ability to control their own behavior (Bandura, 1977). 

In addition, the diathesis-stress model suggests that a genetic predisposition to a certain trait or disorder may only manifest under certain environmental stressors. One study that supports this model is by Caspi et al. (2003), which found that a genetic variant associated with depression only increased the risk of depression in individuals who experienced significant life stress. The study also found that individuals who did not experience significant life stress were not at increased risk of depression, even if they carried the genetic variant.

Similarly, the genotype-environment interaction model suggests that genetic factors may interact with specific environmental factors to influence personality development. This model proposes that genetic factors may predispose individuals to certain personality traits, but their expression is contingent upon the environment in which they develop. For instance, an individual with a genetic predisposition for shyness may not exhibit this trait if they grow up in a social and outgoing family environment, while the same individual may exhibit shyness if they grow up in a less socially stimulating environment. This model highlights the importance of considering both genetic and environmental factors in understanding personality development. The study by Caspi and colleagues (2003) mentioned above, provides evidence for the genotype-environment interaction model in relation to the development of antisocial behavior. The study found that individuals with a specific gene variant were more likely to exhibit antisocial behavior only if they experienced childhood maltreatment, highlighting the interaction between genetic and environmental factors in the development of personality traits.


The interactionist perspective emphasizes that personality is not solely determined by either nature or nurture, but rather by the complex interplay between the two.


In conclusion, personality is a complex and multifaceted construct that is influenced by a variety of factors, including genetics, environment, and life experiences. While some theories emphasize the role of genetics or environmental factors in shaping personality, interactionist theories suggest that both factors interact to shape an individual’s unique personality. Understanding the origins of personality can help us better understand ourselves and others, and may even inform strategies for personal growth and development.


Bandura, A. (1977). Social learning theory. Prentice-Hall.

Caspi, A., Sugden, K., Moffitt, T. E., Taylor, A., Craig, I. W., Harrington, H., … & Poulton, R. (2003). Influence of life stress on depression: moderation by a polymorphism in the 5-HTT gene. Science, 301(5631), 386-389. https://doi.org/10.1126/science.1083968

DeYoung, C. G., Hirsh, J. B., Shane, M. S., Papademetris, X., Rajeevan, N., & Gray, J. R. (2010). Testing predictions from personality neuroscience: Brain structure and the Big Five. Psychological Science, 21(6), 820-828.

Freud, S. (1915). The unconscious. The standard edition of the complete psychological works of Sigmund Freud, Volume XIV (1914-1916): On the history of the psycho-analytic movement, papers on metapsychology and other works, 159-215.

Jang, K. L., Livesley, W. J., & Vernon, P. A. (1996). Heritability of the Big Five personality dimensions and their facets: A twin study. Journal of Personality, 64(3), 577-591.

McLeod, S. (2018). Psychodynamic approach. Simply Psychology. Retrieved from https://www.simplypsychology.org/psychodynamic.html

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