Biological explanation: Genes

Question 1

What do family studies into SZ show us?

Answer 1

That the risk of developing SZ increases in line with genetic similarity to a family member who has it.

Question 2

What does Gottesman’s study into family genetics of SZ show?

Answer 2

That there is a 9% chance of a sibling developing SZ if their sibling has it.
Increasing to 48% if they are monozygotic twins.

Question 3

However, what does this mean if the concordance rates aren’t 100%?

Answer 3

That there must be some environmental factors.

Question 4

What is a candidate gene?

Answer 4

A genetic variation that could explain SZ.

Question 5

Is SZ polygenic?

Answer 5

Yes

Question 6

What does it mean if SZ is aetiologically heterogenous?

Answer 6

That different combinations of factors can lead to the same condition.

Question 7

Explain the results of the study showing the link between paternal age and the risk of SZ.

Answer 7

There is a positive correlation between paternal age and development of SZ. (the older the father, the higher the risk).

Question 8

One strength of this explanation is that there is research support for the increase of developing SZ depending on how close they are.

Answer 8

• Tienari et al: showed that biological children of parents with SZ are at a heightened risk of it, even if they are adopted.
• Another study has shown a higher concordance rate for identical twins.
• Some are more at risk because of their genetics.

Question 9

A limitation of this explanation is that it fails to consider the potential environmental factors.

Answer 9

• The concordance rates of less than 100% show that environmental factors must also be present.
• Psychological influences such as childhood trauma could also provide vulnerability.
• Genetics alone can’t explain SZ.