BIOLOGICAL APPROACH Flashcards
The Influence of Genes
The Biological approach assumes everything psychological was first biological and so to understand human behaviour we have to look at the biological structures within them.
The Influence of genetics
Typically each individual is born with 23 pairs of chromosomes which they get from their biological parents, these are our genotypes. These form our DNA, which carries instructions for our characteristics
Biological psychologists believe that our genetics influence our behaviour e.g. intelligence is inherited in the same way that height is
To investigate our genetic influence, twin studies are used and concordance rates are analysed, to show the extent to which twins share the same characteristic/s
If a characteristic is genetic, it would be expected that all MZ twins would share the characteristics as they share 100% of their genetics
McGuffin et al. (1996) found there was a 46% chance if one twin had depression, that the other twin would also have it. This suggests there is a genetic component to illnesses such as depression
Evaluation points
The biological approach is deterministic, meaning it sees everything is pre-determined by genetics and biological structures, this is a simplistic view and ignores the effects the environment has on the development
However, the biological approach has many real-world applications, such as the success of drug therapies, like antidepressants, in treating psychological disorders
EXAM TIP
It is important to remember the biological approach has always played an important role in psychology, however, due to technological advances, allowing the study of the body and brain scanning techniques, it has increased psychologists understanding of the genetic basis of behaviour.
When discussing the strengths and limitations of the biological approach, it is important to acknowledge this and the development it has had on treatments.
Biological psychologists recognise the importance of biological structures and neurochemistry in the body and the role it plays in behaviour
Endocrine system
A chemical messaging system throughout the body
Releases hormones into the bloodstream
Pituitary gland:
Controls the release of hormones from other glands
known as the master gland
Adrenal gland:
releases adrenaline/ noradrenaline as part of the fight/ flight response
Reflex arc
Collection of cells that transmit information
Decide response
Make response happen
Sensory neurons:
Send information from the sense to the brain
Relay neurons:
Connects with other neurons
Analyses sensations
Decides on responses
Acts between the sensory and motor neurons
Motor neurons:
Sends messages from Axons along the brain to the muscles
Synapse
Found at the end of the cell
Synaptic transmission allows neurons to communicate by passing chemical signals/messages between them
The chemical messengers released are called neurotransmitters
There are two types of neurotransmitters
Excitation: Excitatory neurotransmitters increase the likelihood of a new action forming in the postsynaptic cell When the receptors are detected, the electrical charge inside becomes more positive and likely to fire, known as depolarisation
Inhibition: Inhibitory neurotransmitters decrease the likelihood of a new action forming the postsynaptic cell
When the receptors are detected, the electrical charge inside becomes more negative and less likely to fire, known as Hyperpolarisation
The Process of synapse transmission
The action potential travels down the axon of the presynaptic neuron
This forces vesicles containing neurotransmitters to merge with the cell membrane and release the neurotransmitter into the synaptic cleft
Receptors on the postsynaptic neurones dendrite membrane detect the presence of neurotransmitters, changing the chemistry of the postsynaptic neurone
If the change inside the postsynaptic neurone passes a threshold, new potential forms and the message passed on
The neurotransmitters detach from the receptors and return to the presynaptic cell via transport proteins, this process is called reuptake
Nervous systems in the body
The Nervous System
The collection of nerve cells that sends electrical messages around the body
Central Nervous System
Contains the brain and spinal chord
Receives information, processes it and makes decisions
Peripheral Nervous System
Information across the body to the brain
Sends decisions from the brain to the body
The Brain
The brain has different regions which perform different tasks for the body, this is known as localisation of brain function
Brain Stem
Connects the brain to the spine and rest of the body
Regulates basic functions such as breathing, heart rate, eating and sleeping
Temporal Lobe
Controls hearing/ auditory perception
Controls speech comprehension, processing sounds and noise to speech
Frontal Lobe
Predicts future consequences
Decides appropriate behaviours
Cerebellum
Receives information from the spinal cord, sensory systems and other parts of the brain
Regulates balance and motor movements
Cerebral Cortex
The largest area of the brain
Controls; cognition, perception, consciousness, memory, attention, awareness, thought and language
Occipital Lobe
Processes visual stimuli, such as colour, orientation and shape
Parietal Lobe
Regulates sensory information from across the body
Genotype
This is our genetic makeup, the particular set of genes a person possess
Everyone has a unique genotype (apart from MZ who share 100% of their DNA)
On average, a individual has around 100,000 genes
One genotype determines certain characteristics such as eye and hair colour
Phenotype
The expression of the genes
This is the characteristics of an individual determined by both their genes and how they are expressed in their environment
An individual’s genotype will determine how tall they could potentially growl however, environmental factors, such as nutrition will determine whether or not they reach their maximum height
Additionally, an individual may be predisposed to a certain behaviour e.g. criminality but this behaviour may only be expressed if specific environmental factors are in place e.g. lack of money; mixing with the ‘wrong’ crowd
AO1 = 6 marks
For 5-6 marks the answer should clearly and concisely explain what the term means, giving examples and linking each example to explicitly to the role of genetics in explaining behaviour. Effective use of examples should be given to illustrate each point made. There should be confident use of terminology
Possible answer content could include:
A genetic basis to behaviour is part of the Biological Approach, rooting behaviours in physical/physiological contexts, including evolutionary psychology
Both physical and internal (e.g. mental) characteristics are inherited. Traits present in current behaviour may be present as evolutionary processes have selected the most adaptable and useful genes for continued survival
Some traits are innate rather than being the product of environmental influences e.g. physical characteristics such as eye colour, as well as ‘invisible’ traits e.g. having an innate predisposition for musical ability or sporting prowess
Everyone has a genotype which comprises their total set of inherited genes from both parents
The phenotype consists of the ways in which the genotype is expressed and may be influenced by environmental factors e.g. upbringing, nutrition, education
Evolution and behaviour
Evolution refers to changes in inherited characteristics over generations: known as adaptation
Genes are the mechanisms via which evolution takes place
Charles Darwin explained evolution via his theory of natural selection: any genetically determined behaviour which increases a species survival will be passed down to future generations
Natural selection ensures characteristics which will provide an evolutionary advantage (survival and reproduction) are passed down and those that do not die out
Biological psychologists believe characteristics such as intelligence and aggression are adaptive as they enhance human survival and so are part of the evolutionary process e.g. in the animal world aggression, especially in males, signals breeding suitability to potential mates
Some other human behaviours believed to be adaptive are memory and attachment
Memory may be adaptive as it has evolved to enable our survival e.g. memory for faces (‘friend or foe?’)
Attachment to a primary caregiver is adaptive as it increases an infant,s survival rate
