The debate of nature vs. nurture is a centuries long discussion splitting psychologist’s perspectives on human behavior and traits. The nature position of the debate focuses on how DNA and genotype influence behavior and personality. It is essentially hard-wired into your being. On the other hand, nurture leans toward outside influences and interactions shaping your mind. Nurture is founded on the belief that your mind is a blank slate, or a “tabula rasa.” Some psychologists believe in both sides, saying we can be born with traits specific to us, while also acquiring new ones from our environment. Extensive research has been done on this topic with case studies of identical twins and families. Despite efforts and multiple approaches to the matter, there is no one conclusion. If both sides of the argument prove to be intertwined, does one prove to be more influential than the other? “Researchers determined that the average variation for human traits and disease is 49% due to genetic factors and 51% due to environmental factors (Tan).”
The origins of nature vs. nurture came about in ancient Greece. The philosopher, Plato, favored nature, spawning the nativist view claiming that our knowledge was given to us at birth. Contrasting his views, Aristotle created the empiricist view. This side argued that our knowledge was endowed to us through our experiences. The phrase “nature versus nurture” was later coined by Francis Galton in 1874 when he published English Men of Science: Their Nature and Nurture. He wanted to understand the origins of human traits. Galton thought knowing these traits could help to benefit other people. He respectively coined the term “eugenics” which aimed to increase the likelihood of positive traits and decrease the likelihood of negative traits. His cousin, Charles Darwin, also believed in eugenics, publishing On the Origin of Species (1859). They both believed that nature triumphed over nurture in the sense that they thought they could influence individuals with better characteristics to breed with each other to create better people. Galton introduced the concept of twin studies, due to his interest in natural selecting through breeding. This played a pivotal role in nature vs. nurture as a whole. A twin study occurs when you survey a pair of twins that were separated and raised apart from each other. Their traits get compared with each other to test the genetic similarities.
Nature and nurture debates have made substantial progress to science, causing scientists to approach different ways of thinking. Nature falls on the biological side along with psychoanalysis, and would be considered a strict nativist approach. Nurture would be on the humanism and behaviorism side, becoming radical empiricists. Nativism focuses on characteristics being genetically inherited. Psychologists in child development today have used the research from nature and nurture to conclude whether children will develop their traits or are born with them.
There has been the discovery of gene expression, which is the process of how gene sequences create structures, proteins, and other molecules. Using gene expression, scientists are able to distinguish between what traits are inherited to a person, aiding the side of nature. They were able to pinpoint how mental and physical disorders were passed down to offspring. Using biopsychology, researchers are gathering data on how neurotransmitters affect behavior. Despite that, nurture’s argument was backed when it was discovered that certain genes can be activated by the environment you live in and interactions you are faced with. This introduces the concept of epigenetics, which correlates the environment with expression of genes. It is the study of changes in gene expression without the changing of the DNA sequence. Changing in gene expression can be accounted for by numerous aspects including lifestyle, the environment, and age. This disproved that an individual’s genetic sequence completely defined their traits. For example, if you were to have diabetes run in your family, you would be susceptible to that disease as well. If you took the correct care of your body, you would have a lesser chance of expressing that gene in the future. This was a breakthrough for the scientific community, giving rise once more to the empiricist view.
Looking back to twin studies, researcher Beben Benyamin has worked with others to put together a collection of data on nature vs. nurture. “The risk for eating disorders was found to be 40% genetic and 60% environmental, whereas the risk for mental and behavioural disorders due to use of alcohol was 41% genetic and 59% environmental…The risk for bipolar disorder was found to be 68% due to genetics and only 32% due to environmental factors. Weight maintenance was 63% due to genetics and 37% due to environmental factors (Tan).” This showcases how in some aspects environmental influence overtook genetics, and vice versa. Nature versus nurture in regards to mental health is also something developmental psychologists look at. Factors like parenting styles and social interaction play a big role in the probability of mental disorders, though genetics determine the likeliness of receiving that illness. When there is the possibility of contracting a mental disorder, being exposed to nurturing behavior may help the condition develop with less severity. Social Psychologists look into how social media and the effects of peer pressure in society influence behaviors. For example, neurologist James Fallon uncovered he had the brain of a psychopath, but he believed that since he had a positive upbringing, he didn’t allow that gene to fully express itself. Benyamin claimed that social attitudes and behaviors were more influenced by the environment, but aspects like skeletal and psychiatric traits were more genetically inherited.
The Bobo Doll experiment, led by Albert Bandera, was conducted to test whether observation and imitation aided the development of social behaviors. 36 boys and 36 girls between the ages of 3 and 6 were tested for this experiment. The children were pre-tested for aggression and put into groups with similar aggressive levels. The experiment was modeled so there were three rooms of 24 children. The kids in each room were exposed to different scenarios. The children in the first room were exposed to adults playing with a toy, or “Bobo Doll,” in an aggressive way, while another room had adults play with the toy in a civilized manner. The third room had the children be exposed to no adults. The children exposed to aggression reacted more violently than the kids who were not. The female children were more likely to physically respond to male models and verbally respond to female models. The male children were more likely to copy the male models than female models, but the female children did not have a preference. Conclusively, the results agreed with Badura’s behaviorist social learning theory. This theory uses the ideas of conditioning to state that, “…social behavior such as aggression through the process of observational learning (McLeod).”
To apply the theory of nature vs. nurture, there have been numerous case studies over the years, mostly with identical and fraternal twins. Francis Galton himself conducted studies on twins. He published his findings in his paper, ”The History of Twins, As a Criterion of the Relative Powers of Nature and Nurture.” Galton, being a strong nativist, aimed to prove the biological advantage over the environment. He stated that twins should inherit “similar traits from their parents.” Part of his procedure was to see if twins that were similar as children grew to be dissimilar as adults, or if the opposite occurred. He concluded that if the twins were of different genders or fraternal, they were more likely to differ from each other. Out of 35 pairs, he concluded 16 were closely similar, and 19 were very alike. The differences he experienced were within their personalities. A majority of his data resulted in sets of twins having similar height, weight, eye, and hair color. Galton came to two final observations that ended his study. Those being, if twins are similar in childhood and grow up in different environments, they will still be similar as adults, and if twins that were not alike as children and raised in similar environments, they will not be similar as adults. Galton used his study to back up that nature had more of an effect than nurture.
A further case study involved a pair of identical trains that were raised apart from each other at birth. Their names were Jim Lewis and Jim Springer. Once they met at age 39, they discovered that they both were nail biters, had tension headaches, and even drove the same variety of car. This pair of twins was involved in a group of studies ranging from 1979 to 1999. These proved that genetics had an influence on personality. “Environment affected personality when twins were raised apart, but not when they were raised together (Lewis).” Also, it was proven that identical twins have similar postures, while fraternal twins do not. Twins separated at birth and reunited reportedly felt 80% closer to each other than currently family or friends. This is inciting that they had a genetic link inspiring their relationship. A future study found that levels of happiness had a 50% genetic influence. This relates back to Benyamin’s work stating social behaviors were influenced more by the environment. Influence by environment or genetics varies from study to study.
This final case study in regards to congenital amusia, or tone deafness, in a pair of fraternal twins. Both of them were 27 year old females. They were exposed to music from a very young age, and both of them had normal hearing. One of the twins was diagnosed with congenital amusia, meaning she had an irregular pitch and rhythm perception. The twin who was not diagnosed did better with musical and language tasks, while the diagnosed twin did better with visual tasks. Both of the twins had a low scoring pitch memory span and beat perception. If they both had musical history and high intelligence, then why were they scoring low in these tests? In the end this study opened more questions on the topic of tone deafness, as well as nature and nurture. While one twin had the disease, the other did not. This called for a more in depth analysis of people with congenital amusia to see what genes cause only one twin to be affected. This study was the first to report on fraternal twins under these circumstances, and performing tests on more like this could produce the biological answers to these questions.
I feel like nature vs. nurture plays a big role in my life, as it does with everyone’s. Starting with nature, I feel as if I get my general temperament from both my mother and father. We tend to be easy going until we get provoked. My father also struggled from anger issues, which I may have also inherited. We are similar when we get aggravated and how we go about it. Genetically, I did inherit my mother’s height, but not her hair or eye color. I possibly also inherited her intelligence, which could be mistaken for work drive. My brother, on the other hand, most likely got handed down my father’s drive for success. They are not the type of people who do well in school. My mother and father both had more of an addictive personality. They struggled with smoking and alcoholism. We don’t share those same addictions, but I find that I also have a habitual personality. I tend to stray from those substances to prevent that gene from expressing itself. Research backs the statement that reoccuring alcoholism in families may change the way alcohol affects the body.
My siblings and I are all relatively short, which was inherited from my mother. My brother and sister have similar hair and eye colors to my mother, leaving me the odd one out of the gene pool. I have noticed my sister is nothing like my parents temperament-wise, unlike my brother and I. My sister is very carefree, while my brother and I are on the anxious side. The three of us all have a similar sense of humor, raising the question of whether that is because of our bonds or genetics. With our use of social media, we are subjected to similar types of content online. We easily could not agree with each other at all, but due to certain circumstances, all three of us are alike. We have been around each other for our entire lives, so are our behavioral similarities because of our nature or nurture? I believe this would fall under nurture due to the studies showing social media’s influence over society.
Moving on to nurture, I feel like I am personally shaped by friends and surroundings more than genetics. Although, I feel like I inherited a general temperament from my parents, I think outside influences altered that. Due to my upbringing, I feel I am more pessimistic on certain subjects than I should be. As a child, being put down may increase the likelihood of being rude to others. Despite growing up in an aggressive household, I had school to teach me the life lesson of “treat others how you would like to be treated.” I did not turn out to be a bully, but extremely shy with slight social anxiety. This is comparable to the James Fallon case mentioned above. Parenting styles and reinforcement played a big part of the anxiety I feel today. I try to do my best in educational situations to avoid disappointment from other adults. I feel like my friends supported me with this issue, and aided me in not turning out like my parents. Surrounding myself with different groups of people over the years has helped to show me who I would like to be. Having positive outside influences helped to alter my base temperament.
Going back to my mother, I was under the influence of her political views for my early teen years. I took both sides and based them off of her descriptions. As I got older, I started using social media. I saw the views of the public and started to understand more about politics. I understood enough to know I did not agree with my mother’s perceptions anymore. I think social media does influence social traits and behaviors in the newer generations due to the fact people rely on technology nowadays. I also also take into account the type of person I am hearing political banter from. If the person I am speaking with is saying negative things, I question the genuity of their outlooks. Nurture has guided me to be more accepting and understanding of the people around me, despite the upbringing I may have had.
Conclusively, there are plenty of factors that back both the nativist and empiricist approaches on nature vs. nurture. Due to the theory’s history dating back to ancient Greece, there is no lack of scientific research to back it. Psychologists have looked through all of the approaches on the matter ranging from psychoanalysis to behaviorism. This is a debate that may never be fully tackled by researchers. Developmentalists of modern times now believe that one side does not take full charge, but both are working respectively with one another. The question is now “how much” of each side is working side by side. Someone may be influenced more by genetics than environment or vice versa, no one person is the same. Genetic studies cannot confirm that heritability is the sole reason for traits and behaviors. Gene expression and eugenics take nurture into account when regarding social behavior and the possibility of contracting mental or physical diseases. Though, numerous case studies on twins back nature with hereditary characteristics. Psychologists now need to work on how the nativist and empiricist views intertwine instead of how they surpass one another. Psychopathology, or abnormal psychology, studies abnormal cognitions and behavior, leaving people to be “atypical” compared to the rest of society. Using this approach, nature and nurture are both seen to be needed to trigger the development of a mental disorder. Both sides play a major role in shaping how people are. To cease the centuries old debate of either “nature or nurture,” psychologists now have to elaborate on the concept of “nature and nurture.”