Biological approach
To fully understand behaviour, we must look at biological structures and processes within
the body.
The mind lives in the brain meaning all thoughts, feelings and behaviour ultimately have a
physical basis.
The actions of genes, hormones, neurotransmitters, and neurochemical mechanisms must
be understood to explain behaviour
Neurochemistry refers to the action of chemicals in the brain. Much of our thought and
behaviour relies of chemical transmission (occurs using neuro transmitters)
Imbalance of neurochemicals has been implicated as a cause for mental illness (low
levels of serotonin in OCD and over production of dopamine in Sz)
Genetic basis of behaviour
- Twin studies are used to investigate whether certain psychological characteristics
have a genetic basis.
- This is achieved by analysing concordance rates (extent to which twins share the
same characteristics)
- Concordance rates in identical twins are higher than for non-identical twins
(suggesting a biological/genetic basis) > however rates are never 100% so the
environment also has an effect
- This allows us to try and work out how much of human behaviour is inherited and
how much is environmental
Monozygotic (identical twins) share 100% of the same genes
Dizygotic (non-identical twins) share about 50% of the same genes
Genotype – particular set of genes a person possesses presented in each of your cells (not
affected by the environment)
Phenotype – the way genes are expressed through physical, behavioural and psychological
characteristics (comes from interactions between genes and the environment)
- Identical twins have the same genes but different phenotypes
Evolution and behaviour
Tries to understand human behaviour as the result of psychological adaptation and natural
selection, it interested in which behaviours are genetically determined and passed on.
- Darwin’s theory of natural selection: any genetically determined behaviour that
enhances and individual’s survival and reproduction will continue into the further
generation.
- E.g., Seligman’s evolutionary advantage explanation for phobias, we avoid things
that were threats in the past to increase chance of survival (drowning, fire)
- Evolution: the process by which organism change over time as a result of changes in
heritable physical of behavioural traits
To fully understand behaviour, we must look at biological structures and processes within
the body.
The mind lives in the brain meaning all thoughts, feelings and behaviour ultimately have a
physical basis.
The actions of genes, hormones, neurotransmitters, and neurochemical mechanisms must
be understood to explain behaviour
Neurochemistry refers to the action of chemicals in the brain. Much of our thought and
behaviour relies of chemical transmission (occurs using neuro transmitters)
Imbalance of neurochemicals has been implicated as a cause for mental illness (low
levels of serotonin in OCD and over production of dopamine in Sz)
Genetic basis of behaviour
- Twin studies are used to investigate whether certain psychological characteristics
have a genetic basis.
- This is achieved by analysing concordance rates (extent to which twins share the
same characteristics)
- Concordance rates in identical twins are higher than for non-identical twins
(suggesting a biological/genetic basis) > however rates are never 100% so the
environment also has an effect
- This allows us to try and work out how much of human behaviour is inherited and
how much is environmental
Monozygotic (identical twins) share 100% of the same genes
Dizygotic (non-identical twins) share about 50% of the same genes
Genotype – particular set of genes a person possesses presented in each of your cells (not
affected by the environment)
Phenotype – the way genes are expressed through physical, behavioural and psychological
characteristics (comes from interactions between genes and the environment)
- Identical twins have the same genes but different phenotypes
Evolution and behaviour
Tries to understand human behaviour as the result of psychological adaptation and natural
selection, it interested in which behaviours are genetically determined and passed on.
- Darwin’s theory of natural selection: any genetically determined behaviour that
enhances and individual’s survival and reproduction will continue into the further
generation.
- E.g., Seligman’s evolutionary advantage explanation for phobias, we avoid things
that were threats in the past to increase chance of survival (drowning, fire)
- Evolution: the process by which organism change over time as a result of changes in
heritable physical of behavioural traits
