Genetic Explanation for Sz - Biological Explanation Flashcards
What are concordance rates?
Probability that a family member will also develop a disease
e.g. Sz (expressed as a %)
What does the genetic explanation of Sz focus on?
Focuses on idea that Sz is linked to a gene
Passed on in families
What does the genetic explanation suggest about genes and Sz?
Genes predispose individuals to Sz
If we share more genes with a family member and they have Sz it make us more likely to also get Sz
What is the likelihood of 3rd degree relatives developing Sz if one of them has it?
Doubles likelihood of you developing Sz
What is the likelihood of 1st degree relatives developing Sz if one of them has it?
10% chance you will develop Sz
What is the likelihood of MZ twins developing Sz if one of them has it?
share 100% of genes
50-60% chance of developing Sz
What is the supporting evidence/strengths of the genetic explanation for Sz?
Heston (1966)
Tsang et al (1999)
Psychology in society
What is the refuting evidence/weaknesses of the genetic explanation for Sz?
Reductionist
Nature-nurture debate
Rosenthal’s diathesis-stress model of Sz
Why is Heston (1966) supporting evidence for the genetic explanation for Sz?
Heston studied individuals who were born between 1915-1945 to Sz mothers and adopted from birth
Rate of Sz in those born to Sz mothers was 10.6% compared with 0% in those not born to Sz individuals
Supports concordance rate evidence for 1st degree relative
Why is Tsang et al (1999) supporting evidence for the genetic explanation for Sz?
Conducted a case study of 12 adults who were 1st degree relative of patients with Sz
Evaluated for negative and cognitive symptoms of Sz and found it was possible to both identify such symptoms and potentially reverse these using a drug called Risperidone
Supports genetic component of Sz in 1st degree relative
Why is psychology in society a strength of the genetic explanation for Sz?
Recognising genetic aspect of Sz is important for people with a history of Sz in their families
Alerts them that they are at higher risk of developing that disorder themselves
Based on this information they could avoid stressful occupations or drug use that may trigger the condition
Why is reductionism a weakness of the genetic explanation for Sz?
The explanation is an example of genetic reductionism
Focuses on parts rather than the ‘whole’ characteristic
Such genetic explanations ignore environmental factors such as nurture and the role that parenting and stressors may play in the onset of Sz
Why is nature-nurture a weakness of the genetic explanation for Sz?
Only studying individuals within the same environment which doesn’t allow for question between whether Sz is genetic or environmental
Why is Rosenthal’s diathesis-stress model of Sz refuting evidence of the genetic explanation for Sz?
Twin and adoption studies don’t show 100% concordance in people with the same genes
Suggests that something non-biological is at work too, like the environment a person lives in
Genes may give a person a predisposition to develop Sz but a trigger such as stress is needed to bring the symptoms out
