Personality - Genetics or Environment?

Nature vs. nurture. It’s been an ongoing debate for thousands of years and a tiresome one at that. While it is fairly well established that it is more often than not an interplay of the two that contributes to ones overall behaviours, traits and characteristics it is important to recognise the extent to which the environment and ones genetic makeup influence particular traits.When a young child appears cheerful, lively and full of laughter you might hear them being described as a ‘happy baby’, they’ve just been like that since they were born. Conversely, when a young child appears reserved or detached you might hear his or her parents claim that they are ‘just shy’. At this stage, there is usually little, or no influence from the environment on these children’s temperaments, it is almost entirely genetic … so how much of our personality is based on genetics and how much is based on our environment later on in life?One of the best and commonly used methods to study the roles of genes (nature) and environment (nurture) is the use of twin studies. It is often useful to study the similarities and differences of identical twins (whose genetic makeup is identical) and fraternal twins (who share approximately 50% of their genetic makeup). When examining the effects of heritability on the ‘Big 5’ personality traits (extraversion, agreeableness, openness, conscientiousness, and neuroticism) between identical twins who were raised together, 40-50% of this influence could be explained by genetics.Furthermore, identical twins even when raised in separate households were more similar than fraternal twins raised in separate households. It is therefore noteworthy that nature has more influence than parental influence does. Scientists have also found evidence for particular genes that have associations with particular personality traits such as novelty seeking or smoking behaviours.So it is seemingly apparent that genetics do have a meaningful impact on ones personality – however it does not account for personality in its entirety … and neither does the impact of parental influence, so what’s left? Well what is left is everything else. It is events that occur, it is the relationships we form, it is the school we went to or the house we spent our childhood in; it is a combination of all of the accidental, random or unpredictable circumstances that arise throughout our experience of life that have the most profound impact on personality.So … which one wins? Nature or nurture? Well while again, it is essentially a combination of both genes and environment that ultimately work together to shape us into the person that we are today, taken together these findings suggest a convoluted interplay of the two. It can be deduced that while our genes may predispose us to particular personality traits or behaviours, our environment can essentially diminish or amplify them over time. For example, imagine two babies are born; they both have a genetic predisposition for depression however one baby is born into a supportive family, is well socialised and receives constant love and affection. This baby’s genes responsible for the predisposition of depression are therefore not stimulated and a depressive disorder does not develop. The other baby however is born into an unsupportive family, is neglected, finds it difficult to socialise through early childhood and the genes responsible for depression are highly stimulated and therefore result in the development of a major depressive disorder.In summary, the growing body of research suggests that genes do have a substantial influence on ones personality however it is the events, environment and circumstance that will either strengthen or weaken this predisposition.