Applications to Theories to Substantive Topics

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An idea proposed by Lenneberg (1967) that there is a critical period for language acquisition supports Chomsky’s theory that language is innately determined. The observations of Genie, an American child born in 1957 that had suffered extreme deprivation of social interaction and kept in isolation supports this idea. Once Genie was discovered she began to respond to others speech and began to imitate single words. She was able to understand words but had no comprehension of grammatical structure. It is believed that Genie had missed her critical period for language development. (McMahan 2014). Unfortunately there is no validity from this study and it would be ethically wrong to try and repeat or test the study on humans. Genie may also have had learning difficulties or disabilities before she was isolated which would also alter the reliability of the findings.

A similar study to that of Genie, was carried out by Fehrer et al (2009) observing baby Zebra Finches that were bred and kept in isolation. The study was observing the development of the bird’s song. It was found that by the 4th generation of birds the song had developed into the normal song of that particular breed of bird, despite any of them ever hearing the sound of bird song. The study shows that Zebra Finches have some internal innate ability to know what the normal bird song is (Lightbown & Spada 2013). However, weaknesses in the methodology of this study question its reliability. There are also ethical issues with keeping animals in isolation although not as extreme as in the case of Genie. Bird song is not a language so it cannot be generalized to humans although it is a form of communication. The study was carried out in laboratory conditions so does not replicate real-life behaviour.

Chomsky’s theory suggests that children are not actively involved in their own language acquisition. He also reduces language to grammar and disregards semantic features. Bates et al (1975) cited in Gross 2015 argues that very young children are involved in the pre-verbal exchanges they have with others. This would suggest that children are actively accruing language and not just passively absorbing it. From looking at supporting studies and their weaknesses it is possible that the development of language acquisition is partly an innate predisposition but the theory does not take into account the child in its social contexts, therefore the theory alone does not explain how children acquire language.

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References

Elysia McMahan. 2014. The Horrific Story of Genie. [ONLINE] Available at: http://www.firsttoknow.com/the-feral-child-who-suffered-at-the-hands-of-her-sadistic-father/ [Assessed 30 November 15]

Gross, R. (2015) Psychology: The science of mind and behaviour. United Kingdom: Hodder Education.

Henna Lemetyinen. 2012. Language Acquistion. [ONLINE] Available at: http://www.simplypsychology.org/language.html [Accessed 29 November 15]

Lightbown, P.M & Spada, N. (2013) How Languages are learned. Oxford: Oxford University Press.

Saxton, M (2010) Child Language Acquisition and Development. London. Sage Publication Ltd.

TAQ 2 Part B

Evaluation of the genetic theory as the cause of Schizophrenia

Schizophrenia is a condition that disrupts the mind’s ability to function and the sufferer loses touch with reality. Schizophrenia is a very complex disorder and there are many explanations and theories that propose explanations for the causes of the disorder (Gross 2015). The genetic theory states that children of schizophrenic sufferers will inherit a disposition to develop the disorder. Evidence for this theory comes from studies of twins, adoption, and biological families. This essay will evaluate the genetic theory as the cause of schizophrenia, looking at key studies that support and refute the theory. Evaluating the methodology used within the key studies to determine their reliability to support the theory.

Supporting evidence for the genetic theory was found from a study carried out by Gottesman and Shields (1966). They used hospital records covering the previous 16 years to identify people with schizophrenia who had a twin. Around 40 sets of twins agreed to take part in the study. The results showed a concordance rate of 48% for identical twins and 17% for non-identical twins. Exact figures varied depending on the type of schizophrenia (Craig & Bellur 2012). Overall the results concluded that identical twins had a much higher concordance rate than non-identical twins. These findings support the theory that there is a genetic cause for schizophrenia. However, there are weaknesses in the reliability of the study. A large amount of data covering a long period of time means that the study cannot be replicated until new data becomes available. Identical twins are also quite rare, reducing further research opportunities. Using a small sample of twin’s means it is difficult to generalize the results to other people. The results of the study do not show 100% concordance, which means there are other factors that contribute to schizophrenia.

Studies of families are carried out to determine how likely a disorder will occur in one person if others in the same family have the disorder as well. A study carried out by Kendler et al (1985) into the risk of schizophrenia in first-degree relatives of patients that had already been diagnosed with the disorder. They found that individuals were at least 18 times more likely than the control group to have schizophrenia if they were a first-degree relation of a schizophrenic patient. Family studies provide useful evidence that supports the role of genetics in the cause of schizophrenia. However, there are weaknesses in this type of study such as environmental influences that may impact the onset of certain mental disorders are often ignored. Family studies also rely on the comparison of people that have already been diagnosed with the disorder meaning it can be difficult to tell the difference between something that is genetic or environmentally caused (Craig & Bellur 2012).

Adoption studies look at adults diagnosed with schizophrenia who were adopted as infants. Schizophrenia symptoms in biological relatives would support a genetic link whereas symptoms in the adoptive parents suggest a more environmental cause. A study carried out by Tienari (1987) in Finland compared over 100 children whose biological mothers had schizophrenia with a control group whose parents did not