Biological Approach

Question 1

the biological approach

4

Answer 1

views humans as biological organisms

provides biological explanations for all aspects of psychological functioning

interested in the genetic basis of behaviour (how some characteristics can be passed from generation to generation via genes) as well as neurochemistry and hormones

biological influences on behaviour….
• genes — heredity, genotype + phenotype, genetic basis of behaviour
• biological structures — neurons and nervous system, brain, hormones
• neurochemistry — neurotransmitters
• evolution and behaviour

Question 2

influence of genes on behaviour

3

Answer 2

heredity

genotype and phenotype

genetic basis of behaviour

Question 3

what is a gene?

1

Answer 3

part of the chromosome of an organism that carries information in the form of DNA for a particular characteristic such as intelligence

Question 4

GENES: heredity

4

Answer 4

heredity = the passing of characteristics from one generation to the next through genes

the reason why offspring ‘take after’ their parents in terms of psychological characteristics

genes carry the instructions for a particular characteristic such as intelligence or temperament — how this characteristic develops depends partly on the interaction of the gene with other genes and partly on the environment

the extent to which a psychological characteristic is determined by genes or the environment is called the nature-nurture debate

Question 5

GENES: genotype + phenotype

4

Answer 5

genotype = the genetic make up of an individual, a collection of inherited genetic material passed from one generation to the next

phenotype = the observable characteristics of an individual, the physical appearance resulting from inherited information, the consequence of interaction between the genotype and the environment

not always a direct relationship between genotype and phenotype — e.g. someone may inherit a recessive gene for blue eyes, but this will not be expressed if they have a dominant gene for brown eyes

in such cases we cannot determine genotype from just observing the phenotype

Question 6

GENES: genetic basis of behaviour

4

Answer 6

each person has a unique combination of genetic instructions, so we differ in terms of personality, intelligence, abilities, etc

heritability = the amount of variability in a trait within a population that can be attributed to genetic differences between individuals within that population

the more a trait is influenced by genetic factors, the greater its heritability

for example, studies of identical twins have suggested that variation in individual intelligence could be 60-80% due to genes

Question 7

influence of biological structures on behaviour

3

Answer 7

neurons and the nervous system

the brain

hormones

Question 8

BIOLOGICAL STRUCTURES: neurons and the nervous system

4

Answer 8

the nervous system is made up of several connected systems…
• CNS — brain and spinal cord
• PNS — somatic and autonomic nervous systems

the nervous system carries messages from one part of the body to another using individual nerves cells known as neurons

neurons transmit nerve impulses in the form of electrical signals

many aspects of behaviour are under neuronal control including breathing, eating and sexual behaviour

Question 9

BIOLOGICAL STRUCTURES: the brain

4

Answer 9

cerebrum = largest part of the brain, makes up about 85% of total brain mass

cerebral cortex = outer surface of the cerebrum, responsible for many higher order functions such as thought and language

cerebrum is divided into 2 halves, known as hemispheres

each hemisphere is further divided into 4 lobes; frontal, parietal, occipital and temporal

Question 10

BIOLOGICAL STRUCTURES: the brain (the lobes)

4

Answer 10

frontal lobe — involved in speech, thought and language

parietal lobe — processes sensory information such as touch, pain and temperature

occipital lobe — processes visual information

temporal lobe — involved in hearing and memory

Question 11

BIOLOGICAL STRUCTURES: how is the brain arranged?

Answer 11

F P

T O

Question 12

BIOLOGICAL STRUCTURES: hormones

4

Answer 12

hormones = chemicals produced by endocrine glands such as the pituitary gland which make up the endocrine system (e.g. testosterone)

the brain sends a signal and hormones are secreted into the bloodstream by endocrine glands

hormones travel to their target cells and stimulate receptors on the surface of or inside cells — this causes a physiological reaction in the cell and alters its activity

Carré et al (2006) studied a Canadian ice hockey team and found evidence of a surge in levels of the hormone testosterone whenever the teams played in their home stadium — suggesting that the hormone energised players to defend their home territory

Question 13

influence of neurochemistry on behaviour: what is neurochemistry?

1

Answer 13

neurochemistry = the study of chemical and neural processes associated with the nervous system

Question 14

NEUROCHEMISTRY: neurotransmitters

6

Answer 14

released by neurons

when a nerve impulse reaches the end of one neuron, a chemical called a neurotransmitter is released

it travels from one neuron to the next across a junction called a synapse

types of neurotransmitter; excitatory + inhibitory

excitatory neurotransmitters = trigger nerve impulses in the receiving neuron and stimulate the brain into action

inhibitory neurotransmitters = inhibit nerve impulses in order to calm the brain and balance mood

Question 15

NEUROCHEMISTRY: neurotransmitters (examples)

3

Answer 15

dopamine = an excitatory neurotransmitter associated with drive and motivation

serotonin = an inhibitory neurotransmitter necessary to maintain a stable mood

Crockett et al (2008) found that when serotonin levels are low, people tend to display increased aggression

Question 16

evolution and behaviour: Darwin’s ideas

3

Answer 16

Charles Darwin’s ideas about biological evolution may apply to human behaviour, allowing us to understand the original adaptive significance of behaviours such as mate selection and aggression

Darwin argued that over time organisms become adapted to their environment through biological evolution

evolution refers to the changes that take place in the characteristics of a population over time

Question 17

evolution and behaviour: what is natural selection?

2

Answer 17

natural selection is the mechanism behind biological evolution

it is the process by which inherited characteristics that enhance an individual’s reproductive success are passed on to the next generation, and so become more widespread in the population over time

Question 18

evolution and behaviour: process of natural selection

4

Answer 18

individuals within a species offer from eachother in terms of physical characteristics and behaviour, at least some of this variation is inherited — those best adapted to their environment will survive

individuals must compete with eachother for resources (mates, food, shelter, etc) and those who survive this competition will go on to reproduce and pass on the behaviours that made them most likely to survive and successfully reproduce

they will pass these behaviours to their offspring and eventually the behaviours will become more widespread in the population

through natural selection, successive generations will develop behaviours that are more likely to lead to survival and reproductive success

Question 19

evolution and behaviour: study

3

Answer 19

Buss (1989) studied 37 different cultures and found universal similarities in human mate preferences

women desired mates with resources (to provide for offspring) and men desired young, physically attractive women (an indication of fertility and reproductive value)

suggests that behaviours that help us survive by enhancing reproductive success are widespread

Question 20

x4 evaluation points

Answer 20

scientific method

useful applications

reductionist

problems with evolutionary explanations

Question 21

evaluation
SCIENTIFIC METHOD

4

Answer 21

the biological approach uses the scientific method, particularly the experimental method, as its main method of investigation

these experimental studies take place in highly controlled environments, meaning that variables are less likely to interfere with results and researchers can easily replicate studies under the same experimental conditions

for example, the biological approach uses sophisticated imaging and recording techniques to study to brain — this increases the precision and objectivity of experimental research in this area

thus adding to the validity and reliability of the original findings and the validity and reliability of the approach as a whole

Question 22

evaluation
USEFUL APPLICATIONS

4

Answer 22

the biological approach provides clear predictions (e.g. about the effects of neurotransmitters or the behaviour of people who are genetically related)

this has led to significant applications of the biological approach to the real world

for example, research into the role of neurochemistry imbalances in depression has led to the development of drug treatments to correct this imbalance and minimise depressive symptoms — thus helping to improve the lives of people suffering from depression by providing suitable treatments

furthermore, research into circadian rhythms and their effect in psychological well-being has led to significant improvements in the working conditions of people working long shifts

Question 23

evaluation
REDUCTIONIST

4

Answer 23

the approach is reductionist as it seeks to explain complex behaviour by breaking it down into its smallest component parts, such as the action of genes, neurochemicals and hormones

for example, many biological explanations of mental disorders are reductionist because genes and neurochemical imbalances are believed to be the main cause of these disorders

this may be problematic as it presents an oversimplified explanation of behaviour and critics argue that we cannot fully understand a behaviour without also taking into account other factors that may influence it

therefore, by not considering cognitive and cultural factors, all of which can significantly influence behaviour, the biological approach may offer an inaccurate explanation of behaviour

Question 24

evaluation
PROBLEMS WITH EVOLUTIONARY EXPLANATIONS

4

Answer 24

most human behaviours can be transmitted by both genetic and cultural routes, so the evolutionary explanation of behaviour is complicated by this additional possibility

critics claim that many established patterns of human behaviour have purely cultural origins with no survival or reproductive value (e.g. the incest taboos that exist in many societies)

the evolutionary explanation emphasises the problems of genetic mutations that arise from inbreeding but incest still exists, despite having no reproductive value — the evolutionary explanation is therefore unable to explain the existence of such behaviour

a large part of the biological approach is the evolutionary explanation, which may not accurately explain all behaviour, therefore the biological approach as a whole may have limited usefulness in explaining behaviour