The biological approach

Question 1

What is the central assumption of the biological approach?

Answer 1

All behaviour has a biological origin (Genes, biological structures, neurochemistry, evolution.)

Question 2

What are genotype and phenotype?

Answer 2

Genotype: Unique genetic profile established at conception.

Phenotype: Expression of genotype influence by interactions with the environment.

Question 3

What are monozygotic and dizygotic twins?

Answer 3

Monozygotic (One egg) - identical twins: share 100% DNA
Dizygotic (Two egg) - non -identical twins: share 50% DNA

Question 4

How are twin studies used to explain behaviour?

Answer 4

• Monozygotic twins share 100% DNA whereas dizygotic twins share 50% DNA.
• Concordance rates (degree of similarity) can be compared.
• A higher concordance rate in monozygotic twins shows a genetic component.

Question 5

The influence of genes: example

McGuffin

Answer 5

McGuffin et al (1996) found a 46% concordance rate in depression in monozygotic twins compared to 5% in the general population. This suggests a genetic component.

Question 6

Define localisation of function

Answer 6

The theory that specific parts of the brain are responsible for specific functions.

Question 7

Describe the role of neurochemistry on behaviour.

Crockett example

Answer 7

• Imbalances in neurotransmitters are associated with atypical behaviour.
• Crockett et al (2008) Abnormally low levels of serotonin are linked with agressive behaviour.
• Indicates this neurotransmitter is important in regulating behaviour and impulse control.

Question 8

Describe the influence of evolution on behaviours.

Answer 8

Natural selection ensures that behaviours that provide an evolutionary advantage are inherited.

e.g. Buss (1994): heterosexual partner preferences:
- Men: young, fertile women, chastity.
- Women: resources, ambition and success.

Question 9

Evaluation

Answer 9

+ The biological approach uses a range of precise and highly objective methods such as FMRI’s and EEG’s.
+ Real world application: understanding abnormal neurochemical activity in the brain has not only allowed for the development of treatments but has provided patients with an explanation for their illness.

– Cipriani et al (2018) compared 21 antidepressants and found a wide variation in their effectiveness.
– Biological explanations are often based on correlational results, which does not mean that one event causes another.