The Biological Approach

Question 1

What does the biological approach assume?

Answer 1

• physiology and biology are at the root of all behaviour
• behaviour is influenced by : -
  §- genes (implies a significant role of evolutionary adaptation)

§- biological structures - nervous and endocrine systems

§- neurochemistry - influence of chemic;s in the brain

Question 2

how many pairs of chromosomes do people have?

Answer 2

23

Question 3

genotype

Answer 3

genetic code that is written in the DNA of all the cells in the body

• dictates characteristics like eye colour

Question 4

phenotype

Answer 4

the expression of the genotype

• physical appearance
• often the result of interaction between the genotype and the environment

Question 5

How can we study the influence of genes?

Answer 5

• family studies

- twin studies

Question 6

how do family studies show the influence of genes?

Answer 6

A particular trait could be found to occur more frequently within a family than within the general population, implying that genetic inheritance has played a role in the trait.

Question 7

example of family studies

Answer 7

Lewis (1936) examined patients with OCD and found that 37% of the patients with OCD had parents with the disorder and 21% had siblings that suffered.

• difficult to tell whether genetic or environment as families spend a lot of time together.

Question 8

monozygotic twins share ___% of their genes

Answer 8

100

Question 9

dizygotic twins share ___% of their genes

Answer 9

50

Question 10

Define concordance rate

Answer 10

The likelihood that the same trait will be present in both members of a pair of twins.

• expressed as a percentage

Question 11

How do twin studies tell us the influence of genes?

Answer 11

There is an assumption that twins share the same environment. Therefore, the difference between concordance rates for MZ and DZ twins tells us how much influence genes have on that trait.

Question 12

What did Nedstadt et al (2010) investigate?

What were the results?

Answer 12

The concordance rate for OCD in MZ and DZ twins

• MZ had 68% concordance rate
• DZ had 31% concordance rate

Question 13

What points can we conclude from the Nedstadt et al (2010) investigation?

Answer 13

1. Genes do play a role in OCD as MZ twins have a higher concordance rate.
2. Concordance rate is not 100% suggesting that other factors must have a role in OCD.

Question 14

what is the central nervous system?

Answer 14

Neurons in the brain and the spinal cored

Question 15

what is the peripheral nervous system?

Answer 15

Neurons throughout the rest of the body

Question 16

What is behaviour the result of ?

Answer 16

The CNS sending electrical messages to muscles, organs, glands etc. to influence a particular response.

Question 17

How does neurochemistry influence behaviour?

Answer 17

When a nerve impulse reaches the end of one neutron, a chemical called NEUROTRANSMITTER is released. It travels from one neuron to the next across a junction called a SYNAPSE.

Different neurotransmitters affect behaviour in different ways.

Question 18

Examples of neurotransmitters -

Answer 18

Dopamine

Seratonin

Question 19

How does the endocrine system influence behaviour ?

Answer 19

• The glands that release hormones into the blood

The nervous system can signal glands to release hormones into the bloodstream which then have effects on our behaviour.

Question 20

Examples of hormones

Answer 20

adrenaline
progesterone
melatonin
testosterone

Question 21

Strengths of biological approach -

Answer 21

• Adopts scientific objective methods of investigation. Therefore, the biological approach is based on reliable data. There is significant evidence for a biological basis to a wide range of traits and disorders.
• Provides clear predictions of behaviour and so it has led to real life applications. Understanding the biological processes in the brain has led to the development of psychoactive drugs that treat mental disorders.

Question 22

Limitations of biological approach -

Answer 22

• Twin studies are often used to provide evidence of a genetic basis to behaviour. However, it is assumed that each twin in a pair experiences the same environment. When in face MZ twins may tend to be treated more similarly then DZ twins leading them to have different environmental influences. So environment found affect the concordance rate as well as genes.
• Some of the explanations are too simplistic and cannot fully explain complex human behaviours. It is said to be reductionist as it reduces behaviour to the most basic biological components (genes and chemicals). Therefore, fails to consider other influences on behaviour e.g. cultural variation.