biological approach Flashcards
what is it
- combines psychology and biology to provide physiological explanations for human behaviour
- tries to explain how we think, feel and behave in terms of physical factors within the body
what is physiology
the study of the body and its parts and how they function
assumptions
- investigates how biological structures and functions of the brain including localisation of function impacts on behaviour
- much of human behaviour has a biological cause which may be genetically or environmentally altered
- genes affect behaviour; genotypes and phenotypes which influence the individual differences between people
- the nervous system including neurotransmitters affect behaviour
- infections of the brain can play a role in mental illness
what is the influence of genes on behaviour
- genes carry instructions for characteristics (personality)
- how it develops depends on interaction of the gene with other genes and the environment- this is the nature-nurture debate
- heritability refers to amount of variation in a trait within a population which can be attributed to genetic differences
- the more a trait is influenced by genetic factors the greater the heritability
- genetics thought to influence risk of mental illnesses
what did francis galton (1869) say
- all natural abilities are inherited
- he later had to agree that any resemblance between family relatives could be a result of both genes and shared environment
twin studies
concordance rate refers to extent to which a pair of twins share similar traits or characteristics
- should be 100% concordance between MZ twins
- DZ twins will show lower concordance rate
what is a concordance rate
agreement between
what is MZ
monozygotic= one zygote
what is DZ
dizygotic= two zygotes
analysis of Bouchard’s twin research
identical twins reared together-86%= higher concordance rate
identical twins reared apart-72%
suggests environment has limited affect on intelligence
non-identical twins reared together-60%
biological siblings reared together-47%
parent and child living together-42%
cousins-15%
unrelated people living apart-0%
same person tested twice-86%
biological structures
- destruction of degeneration of brain cells. caused by: injury, tumours and strokes
- can result in possible behaviour changes
- frontal lobe- parts of speech, reasoning, controlling facial expressions
- the outer layer (cerebral cortex) composed of folded grey matter and playing an important role in consciousness, responsible for many ‘higher order’ functions e.g. thinking
parts of the brain
frontal lobe= thinking, memory behaviour and movement
temporal lobe= hearing, learning and feelings
brain stem= breathing, heart rate and temperature
parietal lobe= language and touch
occipital lobe= sight
cerebellum= balance and coordination
phineas gage
- survived an accident in which a large iron rode went through his brain
- although he survived his personality changed from being sociable to being hostile
- phineas became antisocial, bad manners, tendency for violence
- no treatment
central nervous system
- neurotransmitters enable the NS to function
- abnormal levels can lead to symptoms of mental illness
- depression is linked to low levels of serotonin and noradrenaline whilst schizophrenia is linked to high levels of dopamine
- neurotransmitter levels can be determined genetically
the endocrine system
- hormones are chemical substances that help to regulate processes in the body
- hormones are secreted by glands and travel to their target organs in the blood stream
- hormones cause a physiological reaction in the target cells and alter their activity
several hormones have been linked to behaviour
