Biological Approach

• The Biological Approach says that a person's behaviour is determined entirely by their genetics.
• The Biological Approach suggests that qualities such as intelligence, personality and mental disorders are inherited.
• Twin studies are very helpful to the biological approach because it helps researchers to determine how strong the genetic basis is for certain qualities by looking at the extent to which the twins share the quality (concordance rate)
• Monozygotic twins are identical twins.
• Dizygotic twins are not identical twins
• The Genotype of a person is their genetic composition.
• The Phenotype of a person is the characteristics determined by both genes and the environment (Physical, behavioural and psychological characteristics)
• Darwin's theory of Natural Selection tells us that genetically favourable behaviours are more likely to be passed on through generations, therefore there has to be a large genetic role in determining our behaviour.
• A strength of the Biological Approach is that precise methods are used to obtain data such as FMRI scans, family & twin studies and drugs trials. This makes the data more reliable.
• The Biological approach has real life applications. For example, psychoactive drugs have been developed which have been used to treat mental disorders such as depressions.
• The Biological Approach says that we don't have any control over our behaviour because it is determined by genetics.
• a complication of the biological approach is that if all behaviour is determined by genetics, that makes criminals not morally responsible for their crimes because the blame can be placed on a 'criminal gene'.
• A criticism of the Biological approach is that in family studies, the families have genetic similarities but they also are in the same environment, so similarities could've been caused by nurture rather than nature
• The Nervous system has two functions:

  • Collect and respond to information
  • Coordinate the working of different organs
• The Nervous system has two divisions:

  • Central Nervous System
  • Peripheral Nervous System
• The CNS is made up of two parts: the brain and the spinal cord. The brain is the centre of conscious awareness and the spinal cord acts as an extension of the brain.
• The Peripheral nervous system can be further divided into two parts: The Autonomous nervous system and the Somatic nervous system.
• The Autonomous nervous system is responsible for the involuntary functions of the body such as heart rate, digestion and sexual arousal.
• The Somatic nervous system is responsible for voluntary movement and receiving input from the sensory neurons.
• The Endocrine system is made up of the glands that secrete hormones into the bloodstream.
• The Endocrine system acts more slowly than the Nervous system
• The Autonomous nervous system is in a Parasympathetic state when not stressed.
• When the Autonomous nervous system becomes stressed (through receiving adrenaline), it switched to a Sympathetic state
• The physiological changes caused by adrenaline include:

  • Increased heart rate, breathing rate and blood pressure
  • Digestive system shutting down
• When the threat passes, the ANS changes from a sympathetic state to a parasympathetic state
• The three types of neurone are sensory, motor and relay.
• Motor neurones connect the CNS to the effectors of the body (muscles and glands).
• Motor neurones have long axons and short dendrites.
• sensory neurones carry impulses from the receptors to the CNS.
• Sensory neurones have long dendrites and short axons.
• Sensory neurons have their cell body mid way down the axons.
• Relay neurones connect sensory neurones to motor neurones.
• Relay neurones have short axons and short dendrites
• Dendrites are the branching extensions of neurons that receive information from other neurons.
• Axons are the branching extensions of neurons that send information to other neurones
• the cell body of a neuron contains the nucleus.
• axons are covered in a fatty layer called a myelin sheath, this speeds up the transmission of information.
• Nodes of Ranvier are the gaps in the myelin sheath which help to speed up transmission.
• In a Synapse, electrical signals are converted into chemical signals, those chemicals diffuse across the synapse and are converted back into electrical signals
• The chemicals which diffuse across the synapse are called neurotransmitters.