Biological approach Flashcards
Physiology
The study of the body and its parts and how they function
Purpose of biological approach
The biological approach combines psychology and biology to provide physiological explanations for human behaviour: how we think, feel and behave in terms of physical factors in the body
Assumptions of biological approach
Everything psychological is at first biological
The approach investigates how biological structures and processes within the body impacts on behaviour.
Much of human behaviour has a physiological cause, which may be genetically or environmentally altered.
Twin studies:
Psychologists are interested in studying twins in order to investigate the genetic basis of behaviour:
1. Monozygotic
2. Dizygotic
Monozygotic
One zygote - these twins are formed when a fertilised cell splits into two and forms two separate embryos
Dizygotic-
Two zygotes: these twins are formed when two separate eggs become fertilised by different sperm cells
Concordance rates
Agreement between(refers to the extent to which a pair of twins share similar traits of characteristics)
Concordance rates in MZ and DX twins
There should be 100% concordance rates between MZ twins if a particular characteristic/trait is a genetic one, but DZ twins will show lower concordance rates.
Family studies
Galton agreed any resemblance between family relatives could be a result of both genes and shared environment.
However, with alcoholism for example. there’s a suggestion of a biological predisposition to the addiction(more likely to develop this addiction).
Adoption studies
These studies involve comparing a trait or characteristic between adopted children and their biological or adoptive parents
Selective breeding
This method involves artificially selecting male and female animals for a particular trait.
These animals are then put together in order to breed and produce offspring.
Selective breeding has been used to demonstrate how a number of behavioural characteristics may have a genetic basis e.g. ‘maze bright’ rats
Genes
The basic units of heredity
How do genes function
Genes function in pairs, and the recombination of genes from parents to offspring provides the basis for genetic variability
Phenotype
Observable characteristics of an individual - depending on the interaction of genetic and environmental factors
Genotype
The potential for characteristics, determined by genes
Example of recessive gene
Gene for blue eyes
Example of dominant gene
Gene for brown eyes
Heterozygous
The genotype consists of two different genes
Homozygous
The genotype consists of two genes that are the same
Evolution
The changes in inherited characteristics in a biological population over successive generations
Two main concepts by Charles Darwin in evolutionary theory:
Natural selection
Sexual selection
Natural selection
Animals with particular traits that provide them with an advantage are more likely to survive and reproduce, thereby passing on their ‘adaptive traits’ to their offspring.
These behaviours need to adapt to the environment the animal’s living in, depending on three principles:
1. Principle of diversity
2. Principle of interaction
3. Principle of differential amplication
Principle of diversity
Variety within a species
Principle of interaction
How this variety of species adapt and fit in with the environment
Principle of differential amplification
Those who adapt to their environment will reproduce and those that don’t will die out
Sexual selection
Males have an abundance of sperm and can reproduce with as many females as they want.
Females are limited by the amount of eggs produced, and that she has to carry the baby for 9 months, and then raise the baby until the age of 18.
Females therefore will be more particular about who fathers their children due to the investment they have to make.
If identical twins have a higher concordance rate for characteristics than non-identical twins, why does this suggest a genetic basis for that characteristic?
Identical twins share the same genes, but not the same phenotypes
Biological reason - higher concordance rate between mothers and daughters
Hormones
Chromosome pairs
Egg cells
Non-biological reason for higher concordance rates between mothers and daughters
Bad habits
Learning behaviour
Research methods
- The biological approach draws on concepts from the hard sciences and research tends to be highly scientific in nature.
- The most common methods include laboratory experiments and observations.
- Objective brain recording and scanning techniques were also used
Brain scans
- PET scans
- CAT scans
- MRI
- fMRI
- SQUID magnetometry
PET scans
Positron emission tomography - shows which patterns of the brain are active during a task
CAT scans
Detects damaged parts of the brain, tumours and blood clots
MRI
Detects small tumours and provide detailed information about structure
fMRI
structural and functional information
SQUID magnetometry
Produces accurate images of brain activity by measuring the magnetic fields generated when neurones are activated
Strengths of biological approach
It’s a scientific approach(e.g. fMRIs lead to highly reliable data)
Scientific approach leads credence to study of psychology(as a respectable science)
Impact of biology on behaviour can lead to treatment and intervention to those suffering e.g. anti-depressants
Understanding how an abnormal brain works can shed light on normal brain functioning
