By Chuyin Jin, Year 12
Have you ever wondered where and how your behaviour is shaped? Is it determined by your genetics or your environment? This starts a debate where Nature opposes Nurture. Suppose our behaviour is solely determined by genetics. In that case, it will remain the same during our entire lifetime. If it does not only rely on genetics, our behaviour remains subject to change throughout our development. Yet, the truth is both of those factors have an impact on your behavioural traits from an early age and into adulthood.
The difference between traits developed during upbringing and ones that are directly genetically inherited remains quite unclear, but some studies have found that stable characteristics can be ingrained in a child’s genome and not only adopted from their surrounding environment.
A very famous study that can help us understand this debate is the Minnesota Twins study conducted in 1979, where many twins (identical and fraternal) were separated from each other when they were under 6 months old. This research was conducted on 1500 twins across 11 years. The scientists measured their personality, mental abilities, values, interests, motor skills, reading, spelling, and writing, and found many similarities in identical twins, despite them being raised apart from each other.
Many studies have stated that 20 to 60% of our temperament is determined by genetic components as certain primary genes are involved during brain cell communication, so having certain genes can affect a person’s sociability and predisposition to have certain mental illnesses. It was also found that our personalities evolve as we get older, but our core temperaments, such as agreeableness and openness to experience, do not change much.
Recent findings have also discovered that leadership can be inherited through a specific genotype. Leadership is said to be a skill learned throughout life, but now we say that some people are more predisposed than others for this characteristic.
Our level of distractibility has a genetic aspect as well: disorders such as ADHD are found to be linked with several genes that are passed down in families. Even though we do not know which specific genes have an impact on our distractibility, more than 2000 studies have found a hereditary correlation with ADHD.
Furthermore, during the Minnesota Twins study, it was found that neuroticism, such as the vulnerability to stress, is inheritable: twins with this trait were more sensitive to outside stimuli and twins without this trait had a more calm demeanour.
On the other hand, from the results of the study, it was determined that the need for intimacy is not caused by any genetic factors, but rather by the environment. Children raised in more individualistic environments with a lack of parental affection or attention are less likely to have the desire to engage in very intimate relationships with others, whereas children raised in familial environments will have a strong urge to engage in intimate relationships since that is what they have known and gotten used to.
Interestingly, another study found that patience is greatly influenced by the person’s geographical location. Children residing in more rural areas with fewer stressors are more likely to have more patience, whereas children residing in urban areas tend to have less patience due to the learned ability to be tolerant of uncertainty.
Finally, etiquette is determined by the person’s cultural environment, a person’s etiquette will fully depend on the environment’s morals and beliefs. For example, it is polite to do “la bise” in France when meeting someone, but in Japan, it is seen as polite to bend down to the other person and shake their hand.
In conclusion, an individual’s behaviour is influenced by both nature, which is their genome, and nurture, which is their living environment – your parents cannot fully blame you for some of your behavioural quirks!
