biological approach psyb1. basic assumptions of the biological approach mind and behaviour have a...
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Biological Approach
PSYB1
Basic Assumptions of the Biological Approach Mind and behaviour have a biological basis e.g. the mind
is a result of the way that the brain works. Changing the structure or function of the nervous system
will change behaviour and/or the mind. Behaviour and the mind have evolved e.g. they are
inherited as a result of the action of the genes. To understand mind and behaviour we have to
understand the nervous system and inheritance of characteristics.
Methods of studying brain function Scanning (PET/CAT/MRI) EEG Case studies Post mortem examination of brain Laboratory experiments
Navigation Related Structural Change in Taxi DriversMaguire et al (2000) Taxi drivers given brain scans by
scientists at University College London had a larger hippocampus compared with other people. This is a part of the brain associated with navigation in birds and animals.
The scientists also found part of the hippocampi grew larger as the taxi drivers spent more time in the job.
MRI of Hippocampus
Looking at effects of brain damage from accident, illness or surgery.
Selective Breeding
The intentional breeding of organisms with desirable trait in an attempt to produce offspring with similar desirable characteristics or with improved traits. E.g. Rats have been
selectively bred for intelligence.
Twin and family studies
Tyron (1942)
Exposed a genetically diverse set of rats to a maze. Bred those who made few errors and those who
made many errors together.E.g. MB+MB; MD+MD
Over seven generations the rats made fewer and fewer or more and more errors.
Demonstrated that maze learning could be inherited.
Comparative Psychology
Compares animal physiology and behaviour to humans in order to achieve a better understanding. E.g. Harlow’s studies on the effect of maternal deprivation on infant
monkeys.
Effect of Separation on Infant Monkeys (1958) Is food or comfort the
main driver for attachment?
Infants spent more time on the towelling model.
Biological approach uses a lot of animals in studies, but can we apply our findings to
people? Humans are similar to other mammals: share
DNA and have similar nervous systems – we can apply findings.
Humans are different: more highly developed nervous system, have society, culture, language and creativity – we shouldn’t apply findings.
Evolution & Psychology
Evolutionary psychology regards humans as subject to same evolutionary processes as other animals (continuity)Assumes that behavioural characteristics can
be inherited just like physical onesTries to explain human behaviour/psychology
in terms of evolutionary processes
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Evolution
Each living thing (organism) has a set of characteristics encoded by its genes
The organism inherits its genes from its parent(s)
Variations between organisms are caused by variations in the genotype
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Genotype and Phenotype
Genotype: the genetic material that an individual has. Fixed. Inherited. E.g. potential height
Phenotype: how that genetic material is expressed. Variable. Influenced by environment – diet, toxins.E.g. actual height
Evolution
An organism’s ability to survive depends on how well its characteristics allow it to:Exploit the opportunities available in its
environmentAvoid or deal with the threats presented by its
environment We call this the organism’s fitness
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Fitness
Yummy!
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Arse.Arse.Oops!
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Evolution
Fit organisms are more likely to survive into adulthood than unfit ones.Consequently, they are more likely to mate and
have offspringThey pass on their genes to the next generation
Gradually, the genes for successful characteristics spread through the population
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Why are we attracted to particular types of faces?
Youth + symmetry, skin, eyes = health
Jocelyn Wildenstein has spent $4million on cosmetic surgery.
Inheritance & Biological Structures
The biological approach assumes that genes encode for the structure and function of the nervous system.
This means that behaviour (e.g. phobias) that has evolved has a biological basis. Our brains function so that, for example, most of us keep away from spiders.
Evolution of Psychological Characteristics:
Why are people afraid of spiders?
Afraid of Spiders
Not afraid of Spiders
Keeps away from spiders
Does not keep away, gets bitten and dies
Survives and passes on genes
Dies and does not pass on genes
Evaluation of the biological approach Copy out the table on page 5 of your textbooks
into your notes n.b.: Bi-polar disorder is a mental illness causing swings
between extreme depression and mania. Nature-Nurture debate is the extent to which our
characteristics are inherited (nature) or acquired (nurture).
Look up the definition of the term reductionist on page 61 and write it in your notes so that you understand it.
Environment
Environment contains a range of opportunities and threats (e.g. food
sources, predators)
Evolution
Organism
Organism has particular
characteristics determined by its
genes
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HWK page 30
State, explain, application For example we can study the brain’s
activity during a language task to identify the areas that are involved. This means that we can predict the effects of any damage on language.