The Biological Approach Flashcards
Biological Approach: Key Assumptions
Views humans as biological organisms.
Explains human behaviour in terms of physical factors, including…
Genetics – assumes that behaviour is inherited and recognises the process of evolution.
The Central Nervous System (Brain and Spinal Cord) – explains behaviour in terms of the physical structure and functioning of the brain.
Biochemistry – Chemicals found in the brain (neurotransmitters) and body (hormones) are believed to influence reactions to the environment.
what does heredity mean
Heredity: the passing on of physical or mental characteristics genetically from one generation to another.
Specific genes code for certain physical/mental characteristics.
what does genotype mean
Genotype: The genetic make-up of an individual, which provides the genetic code for how the individual will develop. Each individual is born with 23 pairs of chromosomes.
what does phenotype mean
Phenotype: The observable characteristics of an individual; a consequence of the genotype interacting with the environment e.g. height can be affected by nutrition as well as genes.
Researchers have conducted the following types of studies to examine genetic influences:
Family studies
Adoption studies
Twin studies – comparing monozygotic (MZ – identical, from one zygote) against dizygotic (DZ – non-identical, from two zygotes) twins
Why is it useful to compare MZ and DZ twins?
If a behaviour has a strong genetic basis, then it should be more prevalent amongst MZ twins as they share 100% of their genes, whereas DZ twins only share 50% of their genes.
what is concordance rate
Concordance rate = the probability that a pair of individuals will both have a certain characteristic.
If a behaviour has a purely genetic basis, then the concordance rate should be 100% amongst MZ twins.
KEY STUDY: Gottesman (1991)
What can you conclude from this graph about the role of genes in schizophrenia?
The more closely related you are to someone with schizophrenia, the greater your risk of developing the condition.
KEY STUDY: Gottesman (1991)
Why do you think the risk of developing schizophrenia is higher amongst DZ twins as opposed to ordinary siblings?
Role of the ‘shared environment’ – DZ twins share more environments than ordinary siblings e.g. same friends, class at school
KEY STUDY: Gottesman (1991)
What does the concordance rate found in MZ twins suggest about the role of genes in the development of schizophrenia?
The high concordance rate amongst MZ twins suggests a strong genetic component, but the environment clearly has a part to play. If schizophrenia had a purely genetic basis, then the concordance rate would be 100%.
However, MZ twins are arguably treated more similarly than DZ twins, so nurture could explain the higher concordance rate.
Ultimately, it is difficult to disentangle the role of genes from the environment
What is the evolutionary process?
Over time, organisms ‘adapt’ to their environment.
A genetic mutation may occur randomly, causing a particular physical or psychological characteristic (e.g. intelligence, aggression) to be displayed.
Individuals compete with others for resources e.g. food, mates, and those who are successful are more likely to survive and reproduce, passing their genes (and those behaviours that enabled survival) down to the next generation.
what is natural selection
Natural selection (‘survival of the fittest’) - this characteristic may increase that individual’s chances of survival in their environment i.e. it has adaptive value
what is sexual selection
Sexual selection (‘survival of the sexiest’) - the characteristic has reproductive value i.e. it helps them to gain access to a mate and reproduce
This process takes many generations to occur and so the process of one behaviour becoming part of the genetic make-up of humans is lengthy.
Explain why aggression may have been an adaptive behaviour for our ancestors and why it is still present in the human population today
A genetic mutation may have occurred randomly, causing aggression to be displayed.
The adaptive value of aggressive behaviour to our ancestors:
More successful at hunting (acquisition of resources)
Better able to protect one’s family
Able to protect territory and fend off predators
Successful when competing against other males for access to a female
Consequently, an aggressive male may have been more likely to have survived (natural selection) and been more attractive to a potential partner (sexual selection).
Aggressive individuals were therefore more likely to be successful in passing their genes (along with their aggressive trait) on to the next generation.
Over time, aggression would have become more widespread amongst the population.
what is the The Endocrine System
The Endocrine System: Maintains levels of hormones in the blood and other bodily fluids, using glands throughout the body. Hormones regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.
what are hormones
Hormones: Chemicals produced by endocrine glands.
Hormones are secreted directly into the bloodstream by the endocrine glands, where they travel to their ‘target cells’, stimulating receptors on or inside the cells.
Research demonstrating the effects of hormones on behaviour
Dabbs et al. (1995) studied 692 male prisoners (by taking saliva samples) and found that violent offenders had higher testosterone levels than non-violent offenders. Inmates with higher testosterone levels also violated more rules in prison, especially rules involving overt confrontation.
what is the cerebrum
Cerebrum
This is the largest part of the brain and makes up about 85% of the total mass of the brain.
The outer surface of the cerebrum is called the cerebral cortex, which is responsible for the ‘higher-order’ functions, such as thought and language.
The cerebrum is split into two halves = hemispheres.
Each hemisphere is further divided into four different parts, known as lobes.
what is in the left hemisphere
Left hemisphere:
Language centres…
Broca’s area
Wernicke’s area
Focuses on detail
what is in the right hemisphere
Right hemisphere:
Facial recognition
Recognising emotion
Spatial relationships
Holistic processing
Recognises patterns
The two hemispheres are connected and able to communicate with one another via the….
…corpus callosum
what are the frontal lobes
speech (Broca’s area), thought, learning, conscious movement (motor cortex).
what are the parietal lobes
spatial awareness, sensory information – touch/temperature/pain (somatosensory cortex).
what are the occipital lobes
process visual information (visual cortex).
what are the temporal lobes
memory, recognising faces, language (Wernicke’s area), hearing (auditory cortex)
what is a neuron
Neuron: A nerve cell which transmits information – in the form of electrical signals - between the nervous systems.
what is Neurochemistry
Neurochemistry is the study of chemical and neural processes within the nervous system.
what are Neurotransmitters
Neurotransmitters: chemical messengers within the cerebral (brain) fluid
what is synaptic transmission
is the process for transmitting messages from neuron to neuron.
The synapse is a gap between neurons through which an electrical impulse is transmitted chemically (via neurotransmitters).
Is drug therapy a cure for mental illness?
It could be argued that drug treatments are not actually curing disorders - essentially they are just reducing the symptoms to enable the individual to lead a more normal life.
…which is indicated by the fact that patients often relapse (their symptoms return) within a few weeks if medication is stopped.
A long-term treatment?
Drugs don’t deal with the root cause of disorders – ‘papering over the cracks’ - and so are not necessarily a good long-term treatment option.
Research has shown that the most effective treatment is to combine a drug treatment with a psychological treatment e.g. CBT.
What are some of the side effects associated with drug treatments?
SSRIs (anti-depressant): Nausea, headaches, insomnia, low libido, loss of appetite.
Therefore, it may be the case that the side effects are severe enough to outweigh the benefits of the drug i.e. removing the symptoms.
(P) Due to an increased understanding of the role of neurotransmitters, effective treatments have been developed to help treat mental illness, meaning it has practical applications.
(E) Drugs have been developed to address chemical imbalances in the brain, treating the symptoms of psychological disorders e.g. anti-depressants (SSRI’s e.g. Prozac) to treat depression.
(C) Therefore, it is now possible to make predictions about the effects of certain neurotransmitters on behaviour.
(P) The approach uses scientific methods of investigation,
(E) ….using measures which are largely objective and precise e.g. brain scanning (PET, MRI, CAT) and measuring biochemical levels (saliva/blood/urine samples).
(C) This is a strength because experimental methods take place in highly controlled environments, enabling other researchers to replicate research studies under the same conditions, to check the reliability of the findings.
(P) Arguably the biological approach is too reductionist…
(E) ….because they reduce human behaviour down into its smallest component parts e.g. genes, neurotransmitters, hormones.
(C) In doing so, it fails to recognise the complexities of human behaviour and the role of other factors in influencing behaviour e.g. upbringing, cognitive, cultural and emotional factors.
(P) Furthermore, the approach is limited in that it relies on evolutionary explanations…
(E) This is problematic because some researchers claim that many established patterns of human behaviour have purely cultural origins with no survival or reproductive value e.g. traits we look for in a potential partner/mate.
(C) Ultimately, it is difficult to determine the extent to which a behaviour has an evolutionary or cultural basis, because evolutionary explanations are assumption-led.
