Biological Approach

Question 1

What is the Biological Approach?

Answer 1

• A perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function.

Question 2

Assumptions of the Biological Approach

Answer 2

1. To fully understand human behaviour we must look at biological structures and processes within the body.
2. An understanding of the brain structure and brain function can explain our thoughts, feelings and behaviour. All thoughts, feelings and behaviour have a physical basis.
3. Genes influence behaviour. The genes we inherit from our distance ancestors made biopsychologists think that behaviour and psychological characteristics have evolutionary explanations.

Question 3

Influence of genes on behaviour

Answer 3

• The body is made up of trillions of cells. Within most cells is the nucleus.
• The nucleus of every cell contains 46 structures called chromosomes. 23 pairs which have been inherited from parents are genotype.
• Chromosomes are made up of DNA.
• The DNA on each chromosome carries genes.
• Genes interact with the environment to influence all aspects of bodily structures and function.

Question 4

What is Genotype?

Answer 4

• individuals genetic makeup.
• Occurs at conception and provides genetic code for how individuals develop.
• Each individual is though to have approx 100,000 genes.
• Dictates characteristics such as eye colour.
• Each individual apart from identical twins has an unique genotype.

Question 5

What is Phenotype?

Answer 5

• Product of what happens when genotype interacts with the environment.
• With a physical characteristic such as height the genotype dictates the height and individual can reach but environmental factors such as nutrition will affect the likelihood of them reaching their potential height.

Question 6

Genetic basis of behaviour

Answer 6

• Behavioural genetics are interested in the degree to which psychological characteristics such as personality are transmitted from parent to offspring.
• Some of the well researched human psychological characteristics are thought to be influenced by genes are intelligence, psychology disorders, male and female differences.

Question 7

What are neurons?

Answer 7

• Basic building blocks of the nervous system.
• Are nerve cells which are specialised to receive, process and transmit information to other cells.

Question 8

Nervous system

Answer 8

• Can be split into the central nervous system and peripheral nervous system.

Question 9

Central nervous system

Answer 9

• Made up of brain and spinal cord.

Question 10

Brain

Answer 10

• Brain can be subdivided into many different areas and structures thought to be responsible for certain behaviours such as frontal lobes responsible for functions such as speech, thought and hearing.
• Relies on a large number of chemicals called neurotransmitters to send signals between neurons.
• Too much or too little of these chemicals result in over activity or under activity in various parts of the brain resulting in changes to thinking, feeling and behaviour.

Question 11

Peripheral nervous system

Answer 11

• Made up of neurons that transmit messages or info to and from the CNS.
• Divided into somatic and autonomic nervous system.

Question 12

Somatic nervous system

Answer 12

• Transmits information received by the senses to the CNS and sends messages from the CNS to the muscles.

Question 13

Autonomic Nervous System

Answer 13

• Divided into sympathetic and parasympathetic nervous system.

Question 14

Sympathetic Nervous System

Answer 14

• Increases bodily activities in response to fight or flight.

Question 15

Parasympathetic nervous system

Answer 15

• Maintains or decreases bodily activities from the sympathetic nervous system.

Question 16

What are neurotransmitters?

Answer 16

• Chemical messengers in the brain.
• Transmission of chemicals is via the cerebral fluid.

Question 17

Influence of neurochemistry on behaviour

Answer 17

• When a nerve impulse reaches the end of a neuron, neurotransmitter is released. Travels from one neuron to the next across synapse.
• Many types of neurotransmitters, some trigger receiving neuron to send impulse and some stop from doing so.
• neurotransmitters that trigger nerve impulses into receiving neuron and stimulate brain into action called excitatory neurotransmitters.
• Thos that inhibit nerve implies to calm brain and balance mood are called inhibitory neurotransmitters.

Question 18

Excitatory neurotransmitters

Answer 18

• Dopamine is an example.
• Assocaited with drive and motivation.

Question 19

Inhibitory neurotransmitters

Answer 19

• Serotonin is an example.
• Adequates amounts are necessary to maintain a stable mood.
• Low levels are related to depression.

Question 20

Hormones

Answer 20

• Biochemical stubstances that are produced by glands in the endocrine system.
• In response to a signal from the brain, hormones are secreted directly into the bloodstream by the endocrine glands, where they travel to their ‘target cells’ and exert their influence by stimulating receptors on the surface of or inside cells.
• Produced in large quantities but disappear very quickly.
• Effects are slow compared to nervous system but powerful.
• Examples include testosterone and oestrogen.
• Hormones such as adrenaline are also classed as neurostransmitters.

Question 21

Evolutionary theory of behaviour

Answer 21

• Main principal is that any genetically determined behaviour that enhances individuals survival and reproduction will be passed on in the genes to future generations - naturally selected.
• Occurs because some genetically inherited traits give possessed certain advantages. More likely to survive, reproduce and pass on favourable genes to future generations. If individual survives but no reproduce, genes do not pass on to future generations.

Question 22

What is thought to be naturally selected?

Answer 22

• Aggression.
• Many animal species defend territory through aggression towards own species as protection.
• Means they will have resources necessary for survival, mating and care of offspring. Aggressive behaviour is passed on to offspring.
• Humans show signs of this. Argued that aggression is inherited genetically from ancestors.

Question 23

Evaluation - Deterministic

Answer 23

• Sees human behaviour as being controlled by internal, biological causes meaning that we have no free will. Retz et al concluded that the gene that controls levels of serotonin in the synapse is associated with violent behaviour in male criminals.
• Indicates that violence is part of the criminal’s biology and they do not choose to act in this way.
• Weakness - implications for legal system. One rule of law is that offenders are legally and morally responsible for their actions. If we believe biological approach then offenders are not morally responsible as they are controlled by their genes.

Question 24

Evaluation - Evidence

Answer 24

• Much supporting evidence
• Comes from twin studies using biological equipment such as PET scans.
• Research has found the concordance rates of depression; 49% for monozygotic twins, 17% for dizygotic twins and 9% for ordinary siblings.
• Strength - adds validity and credibility to genetic explanation.

Question 25

Evaluation - Applications

Answer 25

• Approach had lead to treatments being developed for psychological disorders.
• Research into biochemical processors had led to the development of drug treatments. Medication to treat depression and schizophrenia have been developed. Although not effective for all patients, have treated many.
• Strength - sufferers are able to manage to their condition and live a relatively normal life, rather than remain in hospital.

Question 26

Evaluation - Methods

Answer 26

• Methods used are scientific lab studies and studies involve biological equipment.
• To investigate genetic and biological basis of behaviour, approach muses a range of precise and highly scientific methods. Raine et al used PET scans to compare brain activity in murderers and normal individuals. Found differences in areas of the brain such as prefrontal cortex and amygdala, associated with aggressive behaviour.
• Strength - gives psychology greater credibility and status as a science.

Question 27

What does concordance rate mean?

Answer 27

• Extent to which both twins in a sample share a certain disorder/trait/behaviour.

Question 28

Why are twins studies used to support the biological approach?

Answer 28

• To help establish concordance rate between identical and non identical twins to help understand genetic basis of certain behaviours.
• Identical (MZ) are 100% genetically similar.
• Non identical are 50% genetically similar.
• Likelihood of both identical twins having a disorder compared to both non identical twins having disorder indicted how much of behaviour may be genetics.
• If MZ twins have higher concordance rate than DZ twins then argued that there is a genetic explanation.

Question 29

Twin Studies

Answer 29

• Study of intelligence by Bouchard and McGue.
• Complied results of 111 studies.
• Found following concordance rates:
• MZ twins raised together - 87%
• MZ twins raised apart - 72%
• DZ twins raised together - 60%
• Siblings raised together - 47%

Question 30

Evaluation of Research - Perfect Participants

Answer 30

• Identical twins share 100% of genes and non identical twins share 50% of their genes.
• In twins study it can be clearly seen that IQ had a genetic basis due to there being a 27% difference between the concordance rates of identical and non identical twins.
• Strength - ideal sample and provide useful data when supporting biological approach.

Question 31

Evaluation of Research - Same environment

Answer 31

• Problem with twin studies that’s difficult to ignore.
• Identical twins are exposed to similar environmental conditions when being raised. Dressed same and people get them confused. Does not happen with fraternal twins.
• 87% of identical twins in Bouchard and McGue’s twin study would most likely have shared very similar experiences. Perhaps environmental stimuli are the reason they had higher concordance rates that non identical.
• Weakness - Findings could be easily be interpreted as supporting nature rather than nurture.

Question 32

Scientific equipment and scanning techniques

Answer 32

• Approach assumes that behaviour can be explained in terms of activity in brain and nervous system. Biological psychologists seek methods that allow them to view brain activity.
• PET scans, MRI scans and EEG’s used to study structure and functioning of brain.

Question 33

PET scan study

Answer 33

• Raine et al used PET scans to compare brain activity in murderers and normal individuals.
• Found differences in areas of the brain such as prefrontal cortex and the amygdala, regions associated with aggressive behaviour.

Question 34

Evaluation of Research - Objective Data

Answer 34

• Methods favoured by biosphycologists are precise, objective and highly scientific.
• Raines study - psychologists were reading a PET scan. Means data was objective and not open to subjective interpretation.
• Strength - Results add validity to biological approach. Due do scientific equipment, inter rarer reliability is increased. Psychologists will interpret objective results the same.

Question 35

Evaluation of Research - Several weaknesses

Answer 35

• PET scans are costly. Patient has to be injected with a radioactive substance and are less accurate than MRI scans.
• Raines study - invasive method for participants. Before their brain could be analysed they will have had a radioactive substance injected into them.
• Weakness - could cause an already stressed patient more stress.