Nature and Nurture is a highly debated topic on the development of a person’s behaviour and decision-making. John Locke’s quote “Let us then suppose the mind to be, as we say, white paper void of all characters, without any ideas. How comes it to be furnished? Whence comes it by that vast store which the busy and boundless fancy of man has painted on it with an almost endless variety? Whence has it all the materials of reason and knowledge?
To this I answer, in one word, from EXPERIENCE,” is in reference to the nature vs.nurture debate. Locke is supporting the argument of ‘nurture,’ that is, we are born as ‘white paper, void of all characters,’ to which we become ‘furnished’ from the people who surround us, the institutions we live in and our environments that form the basis of who we are. By fully supporting the nature argument, Locke is directly stating that nurture, the hereditary information encoded in a person from birth has no influence whatsoever in a person’s development and that it is entirely nature-responsible.
To disprove Locke’s argument and prove that it is in fact a mix of both nature and nurture in human development, the example of Anti-social behaviour is used. The three main arguments of a cross-sectional study of identical and non-identical twins, the cause of anti-social behaviour and Adoption studies will be used to shed strong doubt on Locke’s ideology that Nurture is the only influence in Anti-social behaviour.
The features of anti-social behaviour include ‘hyperactivity-inattention, novelty- or sensation-seeking, impulsivity, low physiological reactivity, and cognitive impairment,’ (Locke) and Locke supports his argument that Nature is the cause for this through such theories as Piaget’s social cognitive development theory stating that encouragement from parents can develop a child’s attitude towards things such as praising them for taking their first steps which encourages them to do it again.
The first line of evidence supporting ‘Nature’ concerning identical or monozygotic twins, challenges Locke’s argument that ‘nurture’ is the only influential factor in development. The cross-comparison of over 800 sets of identical and 800 sets of non-identical dizygotic twins was conducted in Edinburgh university to measure whether upbringing: nurture, or genetics: nature has a greater effect on the success of people throughout their lives in reference to behaviours specific to people with anti-social behaviour.
The study was led by Professor Timothy Bates, who quotes “Previously, the role of family and the environment around the home often dominated people’s ideas about what affected psychological wellbeing. However, this work highlights a much more powerful influence from genetics. ” The reason that twins are used in this study is because they are traditionally from the same home environments and upbringing, but it is only identical twins which share the same genetic information and one hundred percent of their polymorphic genes.
The study include questions aimed at determining key personality traits such as social skills, learning abilities, self-control and a sense of purpose, all key issues in anti-social behaviour, through application of a well-established psychological scale to measure answers. The researchers of Edinburgh university wrote in the journal of Personality, claiming that “Identical twins are twice as likely as non-identical twins to share the same personality traits, suggesting that their DNA is in fact more influential than their upbringing.
Genetics were most influential on people’s sense of self control, and also affected their social and learning abilities to the same degree as well as restraint and persistence with situations when they got difficult. ’ As stated by Bates, the comparison of twins with identical twins in regards to their social and behavioural reactions conflicts Locke’s argument of nature being more influential than nature, as it is disproved by the fifty percent increase in like behaviour in identical twins based entirely on their genetic makeup and not on their upbringing.
The second line of evidence used to argue Locke’s ideology of Nature being the total influence in regards to anti-social behaviour is from American psychologist, Michael Rutter. He supports the idea that anti-social behaviour is acquired through a shared ratio of nurtured influence and genetic inheritance: “For example, genetic studies have been important in demonstrating that antisocial behaviour associated with early onset hyperactivity-inattention, poor peer relationships, and widespread social malfunction has a strong genetic component, whereas antisocial behaviour without these accompanying problems is largely environmental in origin.
Such findings have been informative in showing that the genetic component is greater in the case of antisocial behaviour that persists into adult life than in antisocial behaviour confined to the teenage period. ” The argues that anti-social behaviours such as hyper activity-inattention are strongly genetic-received, and that this genetic type of anti-social behaviour is persistent later in
life, while including that anti-social behaviour can be largely environmental in terms of short term anti-social behaviour that is confined mainly to adolescence. Rutter claims that his findings on genetic anti-social behaviour across the longer time-span induced by nature and shorter time-span induced by nurture ‘show that genetic influences on antisocial behaviour affect the probability that such behaviour will occur rather than determine it directly.
This solidifies the idea that both nature and nurture induced anti-social behaviours are influential factors in deciding the cause of what brings anti-social behaviour on, but, as shown in his previous quote, affect the probability that anti-social behaviour will occur, but do not bring it on directly: that is, anti-social behaviour cannot be put down to one of the two sides of nature or nurture. Rutter’s opinion on the formation of anti-social behaviours being a mix of both nature and nurture challenge Locke’s firm opinion that it is purely from nature that affect anti-social behaviours.
Rutter also uses the example of petty crime to support the argument of nurture over nature, following on from his claim that a percentage of anti-social behaviour can be attained from environmental factors influenced by nurture. “Equally, genetic findings have been important in showing that there is a much weaker genetic component in violent crime than in petty theft. ” This shows that petty crime, an associated offense brought on by short-term anti-social behaviour is largely influential from nature.
By supporting the nature argument, Rutter shows that there is a possibility that anti-social behaviour that is acquired through hereditary can still be influenced by environmental influences, shown by the idea that a person can commit petty crime based on a nature-based anti-social trait, and again supporting that there cannot be a side of nature or nurture that is completely responsible for the formation of anti-social behaviours without the other coming into the equation.
The third line of evidence using anti-social behaviour to shed doubt on Locke’s theory that development is based purely on nurtured influences is the study of Adoption. Adoption focuses on the relocation of a child from their maternal parents to their adopted parents with a completely different environment and influence on the nurture of the child’s development, classified by E. Ann Viding into two groups: ‘Genetic influences are indicated by the association between adoptee and biological relative.
Environmental influences are indicated by the association between adoptee and adoptive relative. ‘ Raymond R. Crowe conducted a test to measure whether or not ‘heredity contributes to the development of antisocial personality using a group of offspring born to female offenders. ’ All 92 females studied were placed up for adoption in their infancy years, divided into 2 groups: forty-six probands with an equal number of controlled adoptees who were later followed up and interviewed when they reached the ages of 18 years and over.
The results of Crowe’s study showed that ‘A significantly higher rate of antisocial personality was found among the probands than among the controls. The non-anti-social probands proved not to be more deviant than the controls. The antisocial probands experienced certain unfavourable conditions in infancy that may be related to the development of antisocial personality, the most notable being the length of time spent in temporary care prior to final placement.
Although the control group was equally exposed to the same conditions, they did not develop a high rate of the disorder. The findings point to the importance of interactions between genetic and environmental factors in the development of antisocial personality. ’ In Crowe’s study, he demonstrates how the controlled and proband adoptee’s underwent the same adoption phase, interview phase, but the variables included their hereditary and environments.
By suggesting that the group with the significantly higher anti-social behaviour qualities was the proband adoptee group, he is stating that the control group, despite being exposed to the same conditions of adoption, did not develop anti-social behaviours, while the proband group was significantly did. By this, it shred’s serious doubt on Locke’s argument that personal development is based only on the nurtured influences as if this was the case, both groups would have a random distribution of anti-social behaviours and not be a systematic set of results as shown in Crowe’s results of the proband group being affected.
By using adoption as a relevant point of argument against Locke, it shows that development of Anti-social behaviours, despite being separated from biological offending mothers, can still develop in an adopted child regardless of their environment in a proband study group and gives credit to nature as an element of influence in development for adopted children. In conclusion, the three arguments of a cross—sectional study of identical and non-identical
twins to demonstrate likeness in anti-social behaviours in genetically exact identical twins and Rutter’s argument on how anti-social behaviours are formed both demonstrate how both Nature and Nurture are vital in development of Anti-social behaviours. The third argument of Adoption demonstrated a more influential Nature-based contribution than Nurture by showing that only one group of adoptee’s suffered from anti-social behaviours, and as a result, raises alongside the other two lines of evidence strong doubt to Locke’s quote that anti-social behaviour is acquired only through Nurture.
Reference list Crowe, R. (1974) An Adoption Study of Antisocial Personality. Arch Gen Psychiatry 1974; 31(6):785-791. doi:10. 1001/archpsyc. 1974. 01760180027003 Haimowitz, A. G. (1974) Heredity Versus Environment: Twin, Adoption, and Family Studies. Rochester institute of Technology, Rochester. Locke, J. (1994) Essay Concerning Human Understanding. Herrnstein & Murray, p. 311 Mcrae, R. Saunders, R. Smith, P.(2000).
Nature over nurture: Temperament, personality, and life span development. Journal of Personality and Social Psychology, Vol 78(1), 173-186. Rutter, M. (1997) Nature-nurture integration: The example of antisocial behaviour. Vol 52(4), 390-398. Science daily (October 2007) Retrieved from: http://www. sciencedaily. com/releases/2007/10/071016131452. htm Viding, E. (2004) On the nature and nurture of antisocial behaviour and violence. N. Y. Acad. Sci. 1036: 267-277.