Biological explanation
The biological explanation suggests that all behaviour has biological origins and is innate.
Behaviour can be explained by studying biological mechanisms and structures such as
neurotransmitters, hormones, genes, and brain structures.
Genetics may play a role in behaviour. Genes are short sections of DNA which codeI for
specific mental and physical characteristics. The genome is the full genetic constitution of an
organism. The phenotype is the physical expression of the genes. This is shown as
observable characters tics. Behaviour follows a heredity mechanism – the genetic
transmission of mental and physical characteristics from generation to generation. This
shows that behaviour is inherited and that it is innate.
The evolutionary explanation suggests that behavioural patterns may have evolved as they
are adaptive to humans. This is due to the natural selection mechanism. Advantageous
alleles increase the organisms’ chance of survival and reproduction which means that the
behavioural trait is more likely to be passed on and the allele will be in greater frequency in
the next generation.
Neurochemical imbalances may explain abnormal behaviour. Neurotransmitters are
secreted from the presynaptic neuron into the synaptic gap. The neurotransmitters diffuse
from a high concentration to a low concentration across the synaptic gap and bind to
complimentary receptors on the postsynaptic neuron. Inhibitory neurotransmitters
hyperpolarize the postsynaptic membrane and make it less likely that an action potential
will fire. Excitatory neurotransmitters depolarize the post-synaptic membrane and make it
more likely that an action potential will fire. Summation (temporal or special) is the
combined effect of the neurotransmitters. If the postsynaptic membrane reaches -55mv
then an action potential will fire. Neurotransmitter imbalances have been associated with
mental disorders. For instances, low levels of the serotonin neurotransmitter are associated
with depression and high levels of the dopamine neurotransmitter is associated with OCD.
Hormones are chemical messengers which travel through the blood to bind to receptors on
target cells and stimulate a physiological response in the cells. Hormone imbalances may
affect behaviour as well as neurotransmitters. In fact, increased levels of testosterone
during menstruation have been associated with many emotional changes and is commonly
nicknamed PMS (Period mood syndrome.)
Brain structures are directly involved in behaviour. Some brain structures are associated
with specific functions. For instance, the Broca’s area is associated with speech production
and the Wernicke’s area is associated with language comprehension. More complex
behaviours may involve the interaction of many parts of the brain. The importance of brain
structures in behaviour is supported by non-invasive neuroimaging techniques such as PET
scans and MRI scans. This provides detailed information about the brain structures involved
in behaviours. These techniques provide information about the levels of brain activity which
can be useful in identifying parts of the brain which are associated with certain behaviours.
The genetic explanation is potentially harmful. It proposes the idea that genes are fate and
thus the idea that there is no aspect of free will in our behaviour. This completely
contradicts the justice system and the use of legal courts. For instance, thse MAOA gene
The biological explanation suggests that all behaviour has biological origins and is innate.
Behaviour can be explained by studying biological mechanisms and structures such as
neurotransmitters, hormones, genes, and brain structures.
Genetics may play a role in behaviour. Genes are short sections of DNA which codeI for
specific mental and physical characteristics. The genome is the full genetic constitution of an
organism. The phenotype is the physical expression of the genes. This is shown as
observable characters tics. Behaviour follows a heredity mechanism – the genetic
transmission of mental and physical characteristics from generation to generation. This
shows that behaviour is inherited and that it is innate.
The evolutionary explanation suggests that behavioural patterns may have evolved as they
are adaptive to humans. This is due to the natural selection mechanism. Advantageous
alleles increase the organisms’ chance of survival and reproduction which means that the
behavioural trait is more likely to be passed on and the allele will be in greater frequency in
the next generation.
Neurochemical imbalances may explain abnormal behaviour. Neurotransmitters are
secreted from the presynaptic neuron into the synaptic gap. The neurotransmitters diffuse
from a high concentration to a low concentration across the synaptic gap and bind to
complimentary receptors on the postsynaptic neuron. Inhibitory neurotransmitters
hyperpolarize the postsynaptic membrane and make it less likely that an action potential
will fire. Excitatory neurotransmitters depolarize the post-synaptic membrane and make it
more likely that an action potential will fire. Summation (temporal or special) is the
combined effect of the neurotransmitters. If the postsynaptic membrane reaches -55mv
then an action potential will fire. Neurotransmitter imbalances have been associated with
mental disorders. For instances, low levels of the serotonin neurotransmitter are associated
with depression and high levels of the dopamine neurotransmitter is associated with OCD.
Hormones are chemical messengers which travel through the blood to bind to receptors on
target cells and stimulate a physiological response in the cells. Hormone imbalances may
affect behaviour as well as neurotransmitters. In fact, increased levels of testosterone
during menstruation have been associated with many emotional changes and is commonly
nicknamed PMS (Period mood syndrome.)
Brain structures are directly involved in behaviour. Some brain structures are associated
with specific functions. For instance, the Broca’s area is associated with speech production
and the Wernicke’s area is associated with language comprehension. More complex
behaviours may involve the interaction of many parts of the brain. The importance of brain
structures in behaviour is supported by non-invasive neuroimaging techniques such as PET
scans and MRI scans. This provides detailed information about the brain structures involved
in behaviours. These techniques provide information about the levels of brain activity which
can be useful in identifying parts of the brain which are associated with certain behaviours.
The genetic explanation is potentially harmful. It proposes the idea that genes are fate and
thus the idea that there is no aspect of free will in our behaviour. This completely
contradicts the justice system and the use of legal courts. For instance, thse MAOA gene
