Personality Development: Nature vs. Nurture
Many researchers have tried to unravel the mystery of how personality is developed. It cannot be narrowed down to one specific cause. Multiple aspects come together to create a personality. “Personality is the unique and relatively enduring set of behaviors, feelings, thoughts, and motives that characterize an individual (Feist & Rosenburg, 2012).” Important aspects of personality include traits and behavior thresholds. Personality is a more extensive term to describe traits because it encompasses specific details that are not considered part of a trait. A trait is a typical tendency to behave in a certain way, and is directly related to behavior (Feist & Rosenburg, 2012). Examples of personality traits include: optimistic, intelligent, confident, adventurous etc. A person will usually react the same to the situations that are similar. A way to explain these tendencies of recurring traits are with behavior thresholds. Behavior thresholds are, “the point at which a person moves from not having a particular response to having one.” A high threshold means that a person does not have a specific tendency to react in a particular way (Feist & Rosenburg, 2012). Although predictions of traits and behavior are part of personality, different aspects shape personality.
Natural selection had an important role in developing personalities that are present in people today. “Human personality traits evolved as adaptive behavioral responses to fundamental problems of survival and reproduction (Feist & Rosenburg, 2012).” As Feist and Rosenburg (2012) explain, people are sensitive to threats because the environments that our ancestors lived in were threatening. Survival and reproduction are crucial to continuing a population. Human traits have come through “survival of the fittest” because only the strongest personalities have been able to continue on. According to Carl Jung there is a male and a female part of personality. He referred to the female part as anima and the male part as animus. Jung also theorized that every person has a male and a female part to personality, but it may not be noticeable because the opposite genders tend to repress contradictory personalities (Feist & Rosenburg, 2012). In accordance to the evolution of personality, prenatal environments greatly affect the personality of a fetus.
Information about the child’s health and personality traits can been recognized as early as in the womb. “The prenatal environment may play a role in shaping personality (Feist & Rosenburg, 2012).” By the movement and heart rate of a fetus doctors can predict whether a baby will have higher levels of anxiety and stress. The stress level of the mother will also have an effect on how the child will react in times of stress. “That is, infants born to mothers who have experienced an unusual amount of stress during pregnancy tend to have impaired stress functions; higher baseline levels of stress hormones; and a faster, stronger, and more pronounced psychological response to stress, all of which persist into childhood (Feist & Rosenburg, 2012).” This means that a child is more likely to experience anxiety and high stress levels because that is what they felt in the womb.
According to Alfred Adler, the order in which children are born can also have a part in developing personality. The first born is more likely to have a sense of superiority and power, but the second child may be more cooperative but be overly competitive. Adler describes the youngest as, “realistically ambitious but pampered and dependent on others (Feist & Rosenburg, 2012).” The argument could be used that the child is being born into a situation which causes them to react as described in the stereotypes of birth order. The two basic arguments used to analyze personality are nature and nurture. “The forces of both nature and nurture shape personality (Feist & Rosenburg, 2012).” Although both forces are existing, one could argue that a single force is more relevant that the other when it comes to personality development.
Analyzing personality development through the nature aspect involves examining and comparing genetics. Comparing genetics and personality within a family may seem like the best study for determining the influence that nature has on personality development but that is not necessarily true. “When considering a family study design, its limitation is that additive genetic and shared environmental influences cannot be separated and it does not provide a heritability estimate but it can show evidence of familial aggregation of personality (Bratko et al., 2014).” Most researchers prefer a variety of environments and biological makeup to compare and contrast to create a more thorough hypothesis and conclusion. In studies, variety is essential in determining how different systems and structures affect personality development. “The biological theories of personality assume that differences in personality are partly based in differences in structure and systems in the central nervous system such as genetics, hormones, and neurotransmitters (Feist & Rosenburg, 2012).” Many other biological theories also agree with the effects that genetics and hormones have on personality. Specifically, the effects that genetics and hormones have on cortical arousal, or how the brain is stimulated, reveals much about a person’s personality. “Evidence supports the connection between central nervous system arousal and personality traits, especially extraversion-introversion (Feist & Rosenburg, 2012).” A variety of methods have been created to discover ways that genetics and nature affect personality in humans.
Techniques have been developed to create a way to connect genetics to personality through a nature perspective. “People differ in their intelligence, personality, and behavior, and a century of research in behavioral genetics has left little doubt that some of this variation is caused by differences in their genomes (Chabris, C. I. et al., 2013).” Genome-wide association studies (GWAS), quantitative trait loci, twin studies, and the five-factor model are all approaches that have been used to research familial aggregation. Typically, GWAS are used to examine and compare genetics to discover disease, but a different study was able to manipulate its works into discovering more about personality. “GWAS have the potential to uncover some of a given traits genetic architecture including the number of genome locations, average effects, and allele frequencies of the DNA variants that affect the trait (Chabris, C. I. et al., 2013).” The study that Chabris et al. (2013) conducted by using genome-wide association studies concluded with a result that supported the idea that many genes make up personality with each one having a small effect.
In addition to GWAS, quantitative trait loci are also focus on genetics and gene location. Quantitative trait loci are considered genetic markers. “Quantitative trait loci (QTL) approach is a technique in behavioral genetics that looks for the location on genes that might be associated with particular behaviors (Feist & Rosenburg, 2012).” By finding the location of genes it can be compared to the behavior of the genes in the same location as the parents. QTL techniques show a high or low level of traits such as anxiety or impulsivity. Along with quantitative trait loci, genetic similarities are usually easier to find in studies of twins. By studying the behavior of twins, both identical and fraternal, genetic makeup is more comparable. “For instance, the trait of extraversion, or outgoingness, often correlates around .50 for identical twins (Feist & Rosenburg, 2012).” Genetic makeup definitely has a role in personality, and some say that it makes up about half of the contributions to personality development. In fact, in Ferguson’s (2010) study he claims that 56% of contributions to antisocial behaviors are results of genetics. Although Ferguson was specifically studying antisocial personalities, some may argue that nature makes up more or less of a person’s individual identity. According to Bratko et al. (2014) genetic makeup contributes between 30% and 50% or personality. Bratko’s group of researchers used the five-factor model to discover genetic relations to one’s personality.
In addition to GWAS, QTL, and twin studies; one of the most commonly used methods to test how nature affects personality is the five-factor model. It is called the five-factor model because there are five categories that are used to analyze the personality through this theory. The categories are openness, conscientiousness, extraversion, agreeableness, and neuroticism (Bratko et al., 2014; Feist & Rosenburg, 2012).” Bratko and his fellow researchers directed a study with the five-factor method which calculated parent-offspring resemblance. They had confidence in this method as stated in the abstract of their study, “… from a genetic perspective, conclusions on family resemblance should not differ depending on the five-factor personality questionnaire (Bratko et al., 2014).” They compared four different families but with different parts of this technique. By using the categories of the five-factor method, they were able to develop a conclusion. “Three measures of parent-offspring similarity (father-offspring correlations, mother-offspring correlations, and midparent-offspring regression) indicate that there is a low to moderate familial aggregation across samples and questionnaires and that even though the effects are mostly small, a part of this similarity is attributed to genetic effects (Bratko et al., 2014).” This means that parents and their children have a tendency to act in the same ways due to the genetics that they share. Along with genetics, nurture has a role in determining how a personality is developed.
The second force is that shapes personality is nurture. The nurture aspect encompasses outside influences such as environment, family life, and culture. “Personality traits produce consistent behavior over time and across situations (Feist & Rosenburg, 2012).” This means that the external forces impact how a person’s individual identity is developed. Many psychologists and theologists would agree that nurture does in fact have a role in the progression of one’s personality. Powledge (2014) stated in her article, “Experience and social environment have a role – probably a key role – in development.” Tabitha Powledge thoroughly studied the effects that nurture has on personality as well as the effects that nurture has on the force of nature. She believes that how people develop a behavior is dependent on how well they remember and learn from past experiences. “The basis of all behavior is learning and memory (Powledge, 2014).” People gain knowledge and experience through different situations that shape their character. Along with memory and learning, Powledge also focused on epigenetics in her article. “Epigenetics – how nurture shapes nature (Powledge, 2014).” A person can be born with specific function and tendencies but nurture shapes these tendencies into personality. She specifically described behavioral epigenetics. “Behavioral epigenetics refers to the study of how signals from the environment trigger molecular biological changes that modifies what goes on in the brain cells (Powledge, 2014).” Basically, it is the study of external factors that alter the way that people think and react to different situations. In addition to epigenetics, familial influences also have a great bearing on how a person discovers their unique character.
The family unit does not have to be blood related, but these are the people who have the greatest influence on one’s development. In was proven through a rat study that parents have an effect on their children even before conception. “When male mice and rats are exposed to alcohol before mating, their offspring do less well at discrimination on spatial tasks, and they are more aggressive, take more risks, and display more anxiety-like behavior than offspring of exposed animals (Powledge, 2014).” The alcohol slightly damages the sperm which will fertilize the eggs of a female. Illegal drugs also cause damage to the future offspring. “Males exposed to cocaine have offspring with smaller brains and deficits in attentions and working memory (Powledge, 2014).” The growing environment of offspring is important even as early as the embryonic development. The mother also has a large impact on the personality development of her babies. If a mother is more nurturing towards her offspring they are less anxious than the offspring that are not nurtured (Powledge, 2014). If a mother is more lackadaisical towards her baby, the baby will have more anxiety. Not only does the parental and familial atmosphere affect the personality of a child, but also the culture in which a child is brought up.
Culture can be described as the location and habits of a particular community or country. For example, when a person is raised in a poor economical culture they are more likely to have a heightened sense of survival than those living in a wealthy suburb. On a bigger scale, there are many contrasting factors of the Western culture when compared to Asian culture. “In particular, people in Asian cultures exhibit qualities that fit a dimension of ‘interpersonal relatedness’ that is rarely seen in Western cultures (Feist & Rosenburg, 2012).” This means that people in the Asian culture tend to be more concerned about the people around them. As a whole, they are more respectful. “Thus, an Asian employee who is offered a promotion that would require relocating to another city may be concerned primarily how the move would affect her family. On the other hand, the primary consideration of the Western employee might be how the move would increase her chances of someday becoming an executive in a major corporation (Feist & Rosenburg, 2012).” As a population, the Western people are more focused on personal success due to the culture that they have been raised in. All in all, the way that a person is raised and where they are raised will affect their personality.
Through natural selection, beginning with life-threatening times, personality has evolved into what it is today. Epigenetics is the best answer to how a person develops personality. Nature and genetics do in fact have an effect on personality, but nurture is the greater force. In Powledge’s (2014) article she states, “The Montreal researchers showed how early experience could shape an adult animal’s behavior and even disease susceptibility, and they attributed these findings to gene changes wrought by epigenetic events.” How a child is treated from the beginning of their life will determine how they will react to others around them. If a child grows up around alcohol and cigarettes they will most like smoke and drink at some time throughout their life. When children are raised around violence and abuse they are often left with an impaired sense of affection towards others. The same goes for personality development; people are molded by their environment. This is recognisable in twin studies.
As mentioned before identical twins have the same genetic makeup, but they typically do not have the same personality. The same genetic information can be altered and manipulated by the situations that a person is placed in. Identical twins have the same DNA, but personalities are different due to the varying interests preceded by the difference in situational learning. Nurture has evolved the force of nature in some cases and is greatly accredited to the development of a person’s thinking and reasoning. In conclusion, both nature and nurture play a role in personality development but evidence suggests that nurture has a slightly greater influence.
Bratko, D., BrkoviA‡, I. ButkoviA‡, A., Kerestes, G., & VukasoviA‡, T. (2014). Personality Resemblance Between Parents and Offspring: Study of Five Factors Across Four Samples and Questionnaires. Journal Of Child & Family Studies, 23(1), 95. doi:10.1007/s10826-012-9695-9
Chabris, C. I. et al. (2013). Why It Is Hard to Find Genes Associated With Social Science Traits: Theoretical and Empirical Considerations. American Journal Of Public Health, 103(S1), S152. doi:10.2105/AJPH.2013.301327
Feist, G. J., & Rosenberg, E. L. (2012). Psychology: Perspectives & Connections (2nd ed.). New York: McGraw-Hill Higher Education.
Ferguson, C. J. (2010). Genetic Contributions to Antisocial Personality and Behavior: A Meta-Analytic Review From an Evolutionary Perspective. Journal Of Social Psychology,
Powledge, T. M. (2011). Behavioral Epigenetics: How Nurture Shapes Nature. Bioscience, 61(8), 588. doi:10.1525/bio.2011.61.8.4