The Biological Approach

Question 1

What are the basic assumptions of the approach? (5 points)

Answer 1

1) Biological structures, and functions of the brain (e.g. localisation of function) impact behaviour.
2) Genes affect behaviour.
3) Nervous system including hormones and neurotransmitters affect behaviour.
4) Infections of the brain play a role in mental illness.
5) Evolution and natural selection play a role in behaviour.

Question 2

What is heritability?

Answer 2

The amount of variation in a trait (behaviour) within a population that can be attributed to genetic differences.

Question 3

The more a trait is influenced by genetic factors the…

Answer 3

Greater the heritability.

Question 4

Genes have been shown to influence behaviour and mental illness give an example.

Answer 4

Twin studies suggest our IQ variance is affected by as much as 60-80% due to genes.

Question 5

What is a monozygotic twin?

Answer 5

Identical twins

Question 6

What is a dizygotic twin?

Answer 6

Non-identical twins.

Question 7

What is concordance rates?

Answer 7

This refers to the extent to which a pair of twins, or other blood relatives, share similar traits or characteristics (generally shown in percentage).

Question 8

What should the concordance rate be between MZ twins if a particular trait/characteristic is a genetic one?

Answer 8

100%

Question 9

What is the concordance rate for DZ twins generally?

Answer 9

Generally lower than MZ twins, usually 50% like other blood relatives.

Question 10

Describe one twin research supporting twin concordance rate.

Answer 10

Holland et al. He found a concordance rate of 56% of MZ twins both suffered from anorexia but only 5% of the DZ twins both suffered. Shows the susceptibility to anorexia has a significant genetic component.

Question 11

What other comparison can be used in twin studies?

Answer 11

If the twins have been raised together or apart.

Question 12

How can the CNS and neurotransmitters influence behaviour?

Answer 12

Abnormal levels of neurotransmitters can lead to symptoms of mental illness. i.e. Depression is linked to low levels of serotonin and noradrenaline whilst schizophrenia is linked to high levels of dopamine.

Neurotransmitters levels can be determined genetically.

Question 13

What do excitatory neurotransmitters do?

Answer 13

They trigger nerve impulses and stimulate the brain into action.

Question 14

What do inhibitory neurotransmitters do?

Answer 14

They inhibit nerve impulses, calm the brain and balance mood.

Question 15

What are hormones?

Answer 15

They are chemical substances that help regulate processes in the body.

They are secreted by glands and travel to target organs in the bloodstream.

Question 16

What do hormones do to their target cells/organs.

Answer 16

Causes a physiological reaction and alter their activity.

Question 17

Give an example of a hormone that has been linked to a behaviour.

Answer 17

Testosterone and aggression have been linked.

Question 18

What does the frontal lobe do?

Answer 18

It controls part of speech, reasoning, facial expressions and emotions.

Question 19

Describe a case which evidenced how different parts of the brain are responsible for different behaviours.

Answer 19

The Phineas Gage case: he survived an accident in which a large iron rod went through his brain. Although he survived his personality changed from being sociable to hostile.

Question 20

What do genes function in and how are they inherited?

Answer 20

Genes function in pairs and the recombination of genes from parents to offspring provides the basis for genetic variability.

Question 21

What do genes carry info in the form of?

Answer 21

Genes carry info in the form of DNA.

Question 22

What do genes determine?

Answer 22

The potential for particular characteristics (genotype).

Question 23

What do the observational characteristics of a person (phenotype) depend on?

Answer 23

The interaction of genetic and environmental factors.

Question 24

What is a persons genotype?

Answer 24

Their genetic make-up.

Question 25

How is a persons phenotype determined?

Answer 25

It is the genetic programming that provides the phenotype. However environmental factors also determine a persons phenotype.

Question 26

What is genotype?

Answer 26

The genetic code that is written in the DNA

Question 27

What is phenotype?

Answer 27

The way the gene is expressed through physical, behavioural and psychological characteristics. Can also be affected by environmental factors.

Question 28

What is a good example were individuals share the same genotype but have a different phenotype.

Answer 28

Identical twin studies. They have the same genetic make-up but are not exactly the same person.

Question 29

What is evolution?

Answer 29

The changes in inherited characteristics in a biological population over successive generations.

Question 30

What two main concepts did Charles Darwin emphasise?

Answer 30

• Natural selection.

- Sexual selection.

Question 31

What is natural selection?

Answer 31

Any behaviour that benefits a species and helps it to survive and reproduce, will continue in future generations.

Question 32

What are the strengths of the biological approach?

Answer 32

• Very scientific, increasing reliability and validity of results.
• Biological explanations can lead to treatments like drugs.
• Objective results.

Question 33

What are the disadvantages of the biological approach?

Answer 33

• Very deterministic.
• Reductionist.
• Dehumanising.
• People may search for ‘criminal genes’
• Ignores the role of environmental factors.
• Laboratory experiments can lack ecological validity.