The Biological Approach

Question 1

What are the assumptions of the Biological Approach?

Answer 1

• Everything psychological has a biological basis.
• Our biology is determined by evolution and genetics.
• To investigate the mind, we must investigate the physical brain.
• To understand human thoughts and behaviour we must investigate biological structures (physiology) and processes (e.g. biochemistry) within the brain and body.

Question 2

What is the genetic basis of behaviour?

Answer 2

The genetic basis of behaviour refers to the idea that specific genes can be responsible for our behaviour.

Question 3

Give an example of this.

Answer 3

For example, compulsive behaviour, as seen in people with obsessive-compulsive disorder, has been linked to the SERT gene.

A faulty SERT gene affects the transport of serotonin, which can create lower levels of this neurotransmitter. If this occurs in certain networks of the brain, it can lead to unwanted thoughts and repetitive behaviours, which are key
symptoms of the condition.

Question 4

What is a genotype?

Answer 4

Genotype refers to the genetic make-up of an individual that is inherited.

Question 5

What is a phenotype?

Answer 5

Phenotype refers to the observable characteristics of an individual that are expressed and is a result of the interaction between their genotype and their environment.

Question 6

Give an example of genotype and phenotype using a faulty SERT gene.

Answer 6

An individual inherits a faulty SERT gene as part of their genotype which makes them vulnerable to developing anxiety. They also experience high levels of stress during a particular period of their life. The interaction between their genotype (genetic vulnerability) and environment (stress) leads to OCD being expressed as their phenotype.

Question 7

What studies are often used to investigate the genetic basis of behaviour?

Answer 7

Twin studies.

Question 8

What is a concordance rate?

Answer 8

The chance that two individuals share a characteristic.

For example, if 10 pairs of twins are investigated and in 9 of the pairs, they both have symptoms of schizophrenia, the concordance rate would be 90%.

Question 9

What do twin studies compare?

Answer 9

Twin studies usually compare the concordance rates of monozygotic (MZ) twins (who share 100% of their DNA) and dizygotic (DZ) twins (who share 50% of their DNA).

Question 10

What findings can be extracted from twin studies?

Answer 10

• If a characteristic is purely genetic, we would therefore expect the concordance rate for MZ twins to be 100% and 50% for DZ twins.
• If the concordance rate is significantly higher for MZ twins this suggests a characteristic is mainly genetic.
• If the concordance rate for MZ and DZ is similar, this suggests a characteristic is determined by the environment.

Question 11

Give an example of a twin study finding.

Answer 11

Gottesman (1991) reviewed over 40 twin studies and found the average concordance rate was 48% for MZ twins and 17% for DZ twins, suggesting schizophrenia is partly genetic.

Question 12

What structure of the body also influences human behaviour?

Answer 12

The Brain.

Question 13

What are the functions of the 4 specific parts (lobes) of the brain?

Answer 13

Frontal Lobe – associated with reasoning, emotions and decision making

Parietal Lobe – associated with perception of stimuli and attention

Occipital Lobe – associated with visual processing

Temporal Lobe – associated with memory and speech

Question 14

Give an example, using individuals who suffer with schizophrenia, that shows the relationship between biological structures and behaviour.

Answer 14

Enlarged ventricles in central brain areas and the prefrontal cortex of the frontal lobe have been linked to negative symptoms of schizophrenia.

Question 15

What are neurotransmitters?

Answer 15

Neurotransmitters are chemical messengers that travel across the synaptic gap during the process of synaptic transmission allowing neurons to communicate.

Question 16

What are imbalances in neurotransmitter levels often associated with?

Give an example of this.

Answer 16

Atypical behaviour.

For example, too little serotonin has been found in patients with OCD, suggesting that serotonin
has a role in preventing the repetition of tasks. A lack of serotonin appears to result in the loss of a mechanism that inhibits task repetition.

Question 17

What is evolution?

Answer 17

Evolution is the process by which successive generations of organisms change.

Question 18

Who proposed the process of natural selection?

Answer 18

Charles Darwin

Question 19

What is natural selection?

Answer 19

A process which suggests that if an organism is able to adapt to its environment, it will be more able to survive and therefore have a greater chance to
reproduce.

Question 20

How can the adaptive characteristics occur?

Answer 20

This adaptive characteristic may occur due to mutation (random variation) when
genes are copied from the parents.

Question 21

What happens in the process of natural selection when the offspring reproduces itself?

Answer 21

When the offspring reproduces itself, the adaptive
characteristic will then be genetically transmitted to its own offspring which will then benefit
from the same characteristic.

This continues for each successive generation. Over time, an adaptive characteristic will become more common throughout a species.

Question 22

Why are adaptive characteristics so useful?

Answer 22

Although this adaptive characteristic is biological, it may underlie a particular way of behaving which helps the organism to survive. Those without the adaptive characteristic (behaviour) will gradually
die out.

Question 23

Give an example of natural selection using attachment.

Answer 23

Attachment is an adaptive behaviour. Human infants are helpless and require adult assistance for a number of years in order to ensure survival. Creating an emotional bond to an adult who will subsequently care for it therefore confers a survival advantage.

Question 24

What is a strength and limitation of the genetic explanation of human behaviour?

Answer 24

Strength
There is supporting evidence from twin studies.

Limitation
Nature and nurture cannot be easily separated.

Question 25

Explain the strength of supporting evidence.

Answer 25

P - A strength of genetic explanations of human behaviour is the supporting evidence from twin studies. E - For example, McGuffin conducted a twin study on depression and found concordance rates of 46% for MZ twins and 20% for DZ twins. E - This suggests depression is at least partly genetic since twins who are genetically identical were over twice as likely to both have the disorder than for non-identical twins. R - This is a strength as evidence supporting the role of genes therefore supports the idea that psychological characteristics are determined by our biology.

Question 26

Explain the limitation of nature and nurture not being easily separated.

Answer 26

P - A limitation of genetic explanations of human behaviour is that research often involves the use of twin studies. E - Since identical twins are usually raised in the same environment, it is impossible to disentangle the role of inherited and environmental influences. E - For example, if a high concordance rate is obtained, we cannot be sure whether this degree of similarity is due to the fact they are genetically identical or the fact they are treated similarly. R - This is a limitation as methodological issues such as these affect the validity of research into biological factors.

Question 27

What are the strengths of the Biological Explanation?

Answer 27

There are practical application of biochemical explanations. The use of laboratory experiments.

Question 28

What are the limitations of the Biological Explanation?

Answer 28

Purely genetic explanations can be considered reductionist. Rather than focus on a purely biological explanation (nature) to human behaviour it may be beneficial to use the diathesis stress model.

Question 29

Explain the strength of practical applications.

Answer 29

P - A strength of understanding about biochemical processes in the brain is that there are practical applications. E - The biological approach has has enabled the development of psychoactive drugs that alter levels of these biochemicals. E - For example, knowing that depressed patients have lower levels of serotonin has led to the development of antidepressants that increase levels of serotonin and can decrease depressive symptoms. E - This practical application shows how understanding biology can help improve people’s lives. R - This is a strength as we can now produce effective treatments.

Question 30

Explain the strength of laboratory experiments.

Answer 30

P - One strength of research into the role of biology on behaviour has been the use of laboratory experiments. E - For example, using the PET scanning method to highlight areas of brain activity is an objective method using scientific measurements. E - Because of this rigorous control, the process meets the criteria of psychology as a science as it removes many extraneous variables that may possibly affect results. E - It also allows for the removal of the subjectivity commonly inherent in measuring emotions. R - This is a strength as it creates confidence in the research findings in order to explain behaviour.

Question 31

Explain the limitation of reductionism.

Answer 31

P - A limitation of the biological approach is that purely genetic explanations can be considered reductionist. E - This means that the approach simplifies the cause of human behaviour down to genetic transmission. E - For example, the approach suggests that everything psychological has a biological basis. E - However, inheriting a particular characteristic in their genome may only make a child vulnerable to develop as their phenotype; certain environmental triggers (e.g. aggressive role models) may also be required in order for the behaviour to be expressed. R - This is a limitation as such purely biological explanations may not account for the interaction of different factors.

Question 32

Explain the limitation of a purely biological explanation. (Diathesis stress model)

Answer 32

**P -** Rather than focus on a purely biological explanation (nature) to human behaviour it may be beneficial to use the diathesis stress model. **E -** This is because the diathesis stress model looks at the interaction between both nature and nurture (environment). **E -** According to this model certain genes leave the individual more vulnerable to developing psychological disorders and whether an individual actually does develop these disorders is influenced by the interaction with an environmental factor (stressor). **E -** This suggests that human behaviour cannot entirely be genetic in origin, at least not in all cases. **R -** This is a limitation as a purely biological explanation may prove to be less useful than an model which looks at the complex interaction between genetics and the environment in order to fully understand human behaviour.