Nature-Nurture debate Flashcards
The nature-nurture debate
The nature-nurture debate discusses the degree to which human behavior such as personality, cognitive traits, personality etc., is a consequence of inherited influence (nature) or a consequence of external influence (nurture).
Nature
The nature idea is that we are pre-wired and our behaviours and traits are all influenced by genetic inheritance and other biological factors.
Several studies on twins and adoptee have been conducted to support the nature view.
Gottesman and Shields (1972)
Gottesman and Shields (1972) reviewed previous research on the genetic transmission of schizophrenia.
The looked at adoption studies (where twins are brought up in different environments) from Kety et al. and more, as well as twin studies (where twins are brought up in the same environment) conducted by themselves. Twin studies looked at both monozygotic (MZ) and dizygotic (DZ) twins.
Findings:
All adoption studies found an increased occurrence of schizophrenia in adopted children with a schizophrenic biological parent.
Kety found that biological siblings of children with schizophrenia showed a much higher percentage of schizophrenia.
Kety also found that if one of the adopted parents developed schizophrenia this did not make it likely for the adopted child to develop it as well
All twin studies found a higher concordance rate for schizophrenia in monozygotic (MZ) than dizygotic (DZ) twins.
In Gottesman and Shield’s own study the rate was 58% for identical twins, and 12% for non-identical twins.
Conclusion
Concordance rates less than 100% show there must be some interaction with the environment.
Gottesman and Shields (1972) evaluation
Large sample – the sample size gives the research a high level of reliability.
Gottesman and Shields (1966)
Generalisable as it includes large sample- both males and females, wide range of ages, both MZ and DZ twins
Nurture
Refers to the idea that our behaviours are a consequence of environmental influence.
The behaviourist approach supports this.
Behaviourism- a theory of learning which states that all behaviours are learnt through interaction with the environment, through a process known as conditioning.
John Locke, believed that when born our mind is a tabula rasa (blank slate) and that the only innate capabilities we are born with are physical.
Watson and Rayner (1920)
Little Albert a young baby, was conditioned to fear a rat.
He was shown a rat (neutral stimulus) and it produced no fear in him
The researchers then paired the neutral stimulus with an unconditioned stimulus (loud noise), which naturally produces a fear response.
Findings:
After several trials, showing the rat a alone would lead to a fear response, even though it had not prior to conditioning.
Conclusion:
This shows that humans can acquire new fears and phobias through classical conditioning.
Evaluation
Generalisability- The experiment was done on a single child - Albert. Usually a sample of one would be considered very unrepresentative, because the baby might be unusual in all sorts of ways. It was later found that
Reliability- study with standardised procedures and can be replicated if needed
Application- flooding, systematic disensitisation
However:
Kendler at al along with many other scientists have conducted research to explore the genetic link of phobias.
Twin studies showed that when one twin has agoraphobia, the second twin has a 39% chance of developing the same phobia. When one twin has a specific phobia, the second twin has a 30% chance of also developing a specific phobia.
Interactionist approach
Considers behaviour to be influenced by both nature and nurture.
All the studies explored so far, although leaning more towards one side, still has not completely excluded the role of the other side, which suggests that all aspects of behaviour are influenced by both nature and nurture.
Piaget’s model of child development
When looking at Piaget’s model of child development it can be seen that not every child goes through the same stages and at the same rate. This is presumably due to the different environments of the children.
Therefore it can be said that the stages are biologically driven but at a rate determined by the environment.
Gottesman and Shields
Gottesman and Shields study show only a 58 per cent concordance rate in MZ twins although they share 100 per cent of the same genetics, which means 42 per cent of both twins having sz has to do with external influence.
DZ twins having less of a concordance rate than MZ twins show that there is still a considerable amount of genetic influence.
