5. nature vs nurture

nature ao1

• suggests that our genes pre-program all our behaviours.

• those who adopted this position were called nativists

• all possible behaviours are present from conception however whilst some are expressed from birth, others are pre-programmed to emerge as we mature.

• Behaviour is caused by innate characteristics, these are the physiological/biological characteristics we are born with, and behaviour is therefore determined by biology.  

• This focuses on the deterministic that suggests all behaviour is determined by genes and biology.

support for nature (ao1) - gottesman and shields

• evidence for Genetic explanations

• in order to determine whether schizophrenia, a serious mental illness has a genetic link, Gottesman and Shields carried out a comprehensive review of twin and adoption studies between 1967 and 1976.

• In adoption studies: compared biological parents and siblings to adoptive parents and siblings.

• In twin studies: compared concordance rates (how often both twins were diagnosed with schizophrenia) for monozygotic (identical) and dyzygotic (non-identical) twins.

findings

• In adoption studies, biological parents and siblings and adoptive parents and siblings were compared to separate out the contribution of genetics and environment on the development of the disorder.  

• All adoption studies found an increased incidence of schizophrenia in adopted children with a schizophrenic biological parent, whereas normal children fostered to schizophrenic parents and adoptive parents of schizophrenic children showed little evidence of schizophrenia.  

• Both these comparisons indicate that there is a significant genetic input into the onset of schizophrenia, but with concordance rates less than 100% there must be some interaction with the environment

nurture (ao1)

• At the other end of the spectrum are the environmentalists – also known as empiricists

• Their basic assumption is that at birth the human mind is a tabula rasa (a blank slate) and that this is gradually “filled” as a result of experience (e.g. behaviorism).

• The nurture argument suggests that people behave the way they do because they are determined by the things other people teach them, the things they observe, and because of the different situations they are in.  

• Like the nature side, the nurture side is also a determinist view as they believe behaviour is solely determined by our environment

support for nurture (ao3)

• Classical conditioning of fear- phobia acquisition: ‘Little Albert’ (Watson & Raynor, 1920).  Before the study little Albert showed no sign of fear response in any situation.  This provides evidence that the environment can be manipulated to create a phobic response & behavioural change.

• Zimbardo - the power of the situation- put people in the right situation and they will become anything

• bandura - Bobo Doll and Aggression in children

relationship between heredity and the environment: interactionism (ao1)

• it is impossible to separate the two influences as well as illogical as nature and nurture do not operate in a separate way but interact in a complex manner.

• It is more often accepted that behaviour is a result of the interaction between nature and nurture, or biology and the environment.  

• One view is that people may construct or contribute to their own environments. E.g, an individual’s characteristics (which may be innate) such as temperament, gender, or level of aggression, may elicit particular responses from other people, which may in turn influence the individual’s behaviour.  

support for interactionism - diathesis stress model

• diathesis stress model is a good example of the interactionist approach.  This model focuses on psychopathology/abnormality and suggest that abnormalities are caused by a genetic vulnerability, however this only becomes apparent when a biological or environmental trigger sets it off

• e.g. Tienarifound that SZ was more likely to be triggered when they had a biological relative with the disorder and had a dysfunctional relationship with their family.

support for interactionism - perfect pitch

• more evidence comes from music.  Perfect pitch is the ability to detect the pitch of a musical tone without any reference. Researchers have found that this ability tends to run in families and believe that it might be tied to a single gene.

• However, they've also discovered that possessing the gene alone is not enough to develop this ability. Instead, musical training during early childhood is necessary to allow this inherited ability to manifest itself.

ao3 - nurture/nature (weakness) - cannot separate heredity and environment

• It’s impossible to ‘tease out’ the influence of the environment, this is complicated by the fact that even siblings within the same family may not have experienced exactly the same upbringing.  

• Dunn and Plomin suggest that we have shared and unshared environments, meaning that siblings experience life events differently such as a parental divorce, this may mean one thing to one sibling but a different thing to another sibling.  

• This would explain why MZ twins reared together do not show perfect concordance rates, which supports the view that heredity and environment cannot be meaningful separated.  This matters because its adds support to the interactionist approach

ao3 another example - cannot separate heredity and environment

• Another example is a disorder called PKU, this is an inherited disorder that prevents phenylalanine being metabolised resulting in brain damage.  

• If detected at birth however children can be given a diet devoid of phenylalanine and therefore brain damage can be averted.