Nature (genetic makeup) and nurture (environment) both impact personality as the result of their complex interplay. Nurture, however, tends to have a larger impact on personality.
The hottest ongoing debate in psychology—whether ‘nature’ (the genetic makeup of the individual) or ‘nurture’ (one’s environment) shapes personality—has now reached an amicable conclusion. Researchers, psychologists and social scientists have agreed that genes, as well as one’s environment, engage in a complex interplay when shaping personality. Understanding the cause of an individual’s personality, behavior and cognition is an area of interest in various fields, including child development, criminal psychology and the study of personality disorders.
Nature refers to the innate tendencies that one is born with. This is largely determined by our genetic makeup or uncontrollable biological factors. Certain physical characteristics are definitely the result of genes (our DNA), like the color of our eyes, skin and hair. However, an assumption that even psychological characteristics are purely based on our genetic makeup has always been seen as risky.
Those who believe in the hereditary factor as being the only shaper of personality are called nativists. Nativists like Chomsky (1965) believed that language is caused by a specific language acquisition device. Another nativist, the infamous psychotherapist Sigmund Freud, proposed that most of our behavior can be explained through two innate motives—aggression and sex.
There is definite evidence that genetic inheritance does shape behavior. How many times have you seen someone’s behavior and felt that they were behaving exactly like their mother or father? The mother is short-tempered and so is the son. The father has the tendency to lie, and so does his daughter. However, we cannot give all control to genes and stop thinking about our behavioral traits. A criminal would not be convicted for a crime if we knew that genes were the sole determiner of his actions. If that were true, then his children should similarly be brought up in jail to prevent further crimes from happening. This is not done because environmental factors play a major role in shaping personality.
On the other end of the spectrum are empiricists, who believe that the mind is a ‘tabula rasa’ or a clean slate, on that is then filled with learning and experience. This means that empiricists believe all psychological traits are learned from one’s environment and the upbringing a child receives.
For example, Albert Bandura’s ‘Social Learning Theory’ states that personality traits like aggression are gained through imitation, exemplified in his famous ‘Bobo Doll’ experiment. In this experiment, preschool children were shown a movie in which the actor was kicking a doll. After the movie, when the same doll was presented in the room, the children started kicking it too.
The geography or the environment can impact how genes are expressed. A study of 13,000 pairs of twins by King’s College London Institute of Psychiatry (2012) concluded that the place where one lives can actually influence genetic expression.
The interplay of nature and nurture
There is no one particular gene that determines intelligence or a good marriage, but rather a combination of many genes (polygenic inheritance) coupled with countless environmental factors. Nature always works with nurture to form a personality. A person may have a genetic predisposition to smoking or depression, but for an individual who has never come across any smoker or experienced any stressful situations in life, the likelihood of their genetic disposition taking control markedly decreases.
Similarly, it is very often seen that even identical twins have very different personalities, even though they have an identical genetic makeup. One may be good in academics (intelligence) while the other may be more inclined towards the performing arts. Various studies on family, adoption and twins (identical and fraternal) suggest a strong correlation of personalities similar to biological parents, but this does not negate the influence of environmental factors.
The nature of the nurture: Research also suggests that the decisions that we make (environment) have a certain biological influence. Individuals select, modify and filter various activities through their genetic disposition. If a child has inherited a desire to sing or dance, the child would naturally be drawn to those activities and would unconsciously choose them over others.
Can we change Nature? Is our genetics the same as destiny?
We all know that our behavioral traits can be changed through counseling and various forms of therapy, but can we change our genetic makeup? Yes we can, or at least, we will be able to in the future through Molecular Genetics. Molecular genetics is the study of which genes are associated with which personality traits. Aided by the Human Genome Project (2010), the location of specific genes in the chromosome can be found. A replacement of these genes can be created through stem cells and can then be put inside the embryo and monitored for desired changes. The created DNA actually wipes or knocks out certain genes. This study has thus far been conducted on mice.
In humans, DNA samples are taken from the inside of the cheeks. The DNA is examined and analyzed for common genes between people who demonstrate similar personality traits. A dye is injected that contains a marker to identify the desired gene. If the gene is present, the solution will bind with the gene, which will then be visible because of the dye. Until now, genes associated with ADHD (attention-deficit/hyperactive disorder), novelty seeking and smoking have been found through molecular genetics.
Although the nature vs nurture debate has slowly come to a close, the question of which affects us more remains. Research suggests that we don’t simply inherit a set of personality traits, since other variables like environmental factors are also in play. These unpredictable environmental factors have the largest impact on personality, but are much harder to control than our genetic code, as we will certainly see in the future!