the biological approach Flashcards
What is a genotype?
genetic makeup of an organism.
What is phenotype?
the way that genes are expressed through physical, behavioural and psychological characteristics
What is the difference between genotype and phenotype?
genotypes influence phenotypes.
phenotype is the result of genes interacting with the environment
True or false: Behaviour results from genetics and the environment.
TRUE
Why are twin studies useful when studying genotype and phenotype?
Monozygotic twins are genetically identical, so twin studies allow us to see the effects of the environment on their phenotype.
What are the assumptions if the biological approach?
behaviour is linked by genes
everything psychological is first physiological
different species of animal can be studied and compared
outline natural selection
suggests any behaviour that will enhance survival and reproduction of species will be passed on
define neurochemistry
action of chemicals in the brain
what do most of our thoughts rely on
chemical transition in the brain
What is a possible cause of an unbalance of neurochemicals?
mental disorders such as Serotine in OCD and dopamine in depression
what is a concordance rate?
The extent to which twins share the same characteristics
which twin share 100% of the same genes?
monozygotic
strength of biological approach
-Real world application- psychoactive -drugs
-scientific methods highly objective
weaknesses of biological approach
Many patients’ psychoactive drugs don’t work
determinism- all human behaviour as governed by internal genetic cause which we have no control over
what is a strength of using twin studies
by studying concordance rates it can be assumed that genetics play a part
what is a negative of twin studies
MZ twins may be more similar because they have spent more time together compared to DZ twins. a more similar environment
what does the nervous system do?
- responds to info from environment
- coordinates working of different cells and organs in body
what are the two sub-systems of the nervous system?
CNS and peripheral nervous system
what does the CNS do?
responsible for all complex commands and decisions
what are the functions of the spinal cord?
extension of the brain responsible for reflex’s
it passes messages to and from the brain and connects nerves to PMS
what does the brain do?
intelligence, senses, body movement and controlled behaviour
what is the role of the PNS
transfers messages via millions of nerves to and from CNS
what is the PNS subdivided into
the autonomic nervous system (ANS) and somatic
what does the autonomic nervous system do?
heart rate
control breathing
control heart rate
stress response
what does the somatic nervous system do?
controls muscle moment
receives information from sense receptors
anything under conscious control
What part of the NS is referred to as the flight or fight response?
the sympathetic division
what does the parasympathetic division do?
relaxes the body and slows many high energy functions
what does the endocrine system control?
controls vital bodily functions
what is a gland?
a tissue that secretes and produces hormones
what is a hormone? how does it travel
it is a chemical messenger produced by gland, effects target organs and travels in the blood
what is the pituitary gland?
controls other glands. it is found at base of the brain
evaluate the biological approach
-Causation strongly implied in explanations that focus on brain structures. This is a problem for biological explanations as the research only tells us there is an association between brain structures and behaviour=only correlational
+Real world application: Drug therapies have been developed for many mental illnesses based on research into neurotransmitters
+Reliable methods of research means that biological evidence is less susceptible to misinterpretation or researcher bias (e.g. fMRI’s, PET scans, drug trials, EEG etc).
-Deterministic approach: Assumes that human behaviours are the result of evolution
What does the biological approach assume about human behaviour?
assumes all human behaviour has a biological origin
Give examples of internal biological structures and processes the biological approach believes is necessary to understand.
Genes
The nervous system
Neurochemistry
Evolution
what is the phenotype influenced by (how can it be expressed)?
genetic inheritance
interaction with environment
what type of studies do geneticists use to assess the impact genes have on the inheritance of behavioural characteristics?
most studies are done through comparisons of concordance rates (CR) between monozygotic (MZ) twins and dizygotic (DZ) twins.
why are monozygotic twins (MZ) studied?
MZ twins are used as they share 100% of DNA
(great comparison in accordance with DZ twins)
Give some examples of studies done with MZ twins.
MZ twins have an increased concordance rate of developing schizophrenia compared to Dizygotic (DZ) twins
McGuffin et al. (1996) found that if one MZ twin has depression the other twin is 46% more likely to also have depression.
What are some examples of imbalances of neurochemicals in relation with mental health.
Abnormally low levels of serotonin- depression, aggression
(Crockett et al, 2008- important in regulating behaviour and impulse control )
Abnormally high levels of dopamine- schizophrenia
