What is the central claim of genetic explanations for anorexia nervosa?

That anorexia nervosa has a heritable component, with susceptibility to the disorder passed through genes.

How do twin studies provide evidence for genetic explanations of anorexia nervosa?

By comparing concordance rates between monozygotic (identical) twins and dizygotic (non-identical) twins to assess the relative contribution of genetic factors.

Why do higher concordance rates for anorexia nervosa in MZ twins compared to DZ twins suggest genetic influence?

Because MZ twins share 100% of their genes while DZ twins share approximately 50%, so if MZ twins show higher concordance, this indicates genes contribute to the disorder.

What do family studies reveal about the prevalence of anorexia nervosa among first-degree relatives of affected individuals?

First-degree relatives of individuals with anorexia nervosa have significantly higher rates of the disorder compared to the general population.

What does it mean to describe anorexia nervosa as polygenic?

Multiple genes each contribute a small amount to overall vulnerability, rather than a single gene causing the disorder.

Which neurotransmitter system has been particularly implicated in candidate gene research for anorexia nervosa?

The serotonin system, including genes affecting serotonin receptors and transporters.

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Eating Behaviour

Biological explanations for anorexia nervosa

4 things to know
Paper 3

Overview

Evidence for heritability, the link to serotonin dysfunction, reported brain differences, and the evaluation of biological explanations.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Study

What evidence suggests anorexia nervosa is heritable?

Process

How is serotonin dysfunction linked to anorexia nervosa?

Key term

What brain differences are reported in anorexia nervosa?

Evaluation

Evaluate biological explanations of anorexia nervosa.

Questions from this subtopic

Each one with the model answer underneath.

1
What is the central claim of genetic explanations for anorexia nervosa?
Model answer
That anorexia nervosa has a heritable component, with susceptibility to the disorder passed through genes.
2
How do twin studies provide evidence for genetic explanations of anorexia nervosa?
Model answer
By comparing concordance rates between monozygotic (identical) twins and dizygotic (non-identical) twins to assess the relative contribution of genetic factors.
3
Why do higher concordance rates for anorexia nervosa in MZ twins compared to DZ twins suggest genetic influence?
Model answer
Because MZ twins share 100% of their genes while DZ twins share approximately 50%, so if MZ twins show higher concordance, this indicates genes contribute to the disorder.
4
What do family studies reveal about the prevalence of anorexia nervosa among first-degree relatives of affected individuals?
Model answer
First-degree relatives of individuals with anorexia nervosa have significantly higher rates of the disorder compared to the general population.
5
What does it mean to describe anorexia nervosa as polygenic?
Model answer
Multiple genes each contribute a small amount to overall vulnerability, rather than a single gene causing the disorder.
6
Which neurotransmitter system has been particularly implicated in candidate gene research for anorexia nervosa?
Model answer
The serotonin system, including genes affecting serotonin receptors and transporters.

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