biological approach

Question 1

What are the main assumptions

Answer 1

• Behaviour is rooted in the physiology and biology of the body; thoughts feelings and behaviour have a physical basis
• The genes an individual possesses influence his/her behaviour
• Behaviour evolves the same way as physical characteristics through the process of evolutionary adaptation
• Behaviour is affected by the central nervous system, which comprises the brain and spinal cord
• Levels of chemicals such as neurotransmitters and hormones are related to a person’s behaviour

Question 2

what’s the influence of genes on behaviour

Answer 2

• Heredity is the passing of characteristics form one generation to the next through genes. Genes carry the instructions for a particular characteristic (e.g. intelligence or temperament)
• Twin studies are used to determine the likelihood that certain traits have a genetic basis by comparing the concordance rates between pairs of twins
• In monozygotic twins (identical, share 100% genes) have a higher concordance rate than dizygotic twins (non-identical, share 50% genes) it suggests a genetic basis

Question 3

How do genotype and phenotype affect behaviour

Answer 3

• The genotype is the genetic code written in the DNA of an individuals cells
• The phenotype is physical, behavioural and psychological characteristic resulting from this inherited information and influenced by environmental factors
• E.g. someone may inherit a recessive gene for blue eyes, but this won’t be expressed if they have also inherited a dominant gene for brown eyes
• E.g. identical adult twins may look different because they have had different levels of exercise, eating habits etc

Question 4

what’s the influence of biological structures on behaviour

Answer 4

• The main biological structure that influences behaviour is the nervous system
• The nervous system is compromised of several connected systems; the central nervous system compromises the brain and spinal cord, and the peripheral nervous system comprises the somatic and autonomic nervous system
• Neurons carry messages from one part of the body to another through the nervous system
• The brain is divided in to two hemispheres, with each hemisphere further divided in to four lobes
• Localisation of function in the brain suggest that there are separate parts of the brain used for different tasks, and that therefore, if there is damage to part of the brain, this will affect the behaviour associated with this part

Question 5

how does neurochemistry influence behaviour

Answer 5

• Neurochemistry is the biochemistry of the central nervous system
• Hormones are the chemicals which travel through the blood
• Neurotransmitters are the chemicals which travel through cerebral fluid
• Examples on how these can affect behaviour are the hormone testosterone leading to someone being more aggressive, and the neurotransmitter dopamine being related to positive characteristics of schizophrenia

Question 6

Evolution and behaviour

Answer 6

• The mechanism behind biological evolution (changes in the characteristics of a population over time) is natural selection
• Individuals within a species differ from each other in terms of their physical characteristics and in their behaviour, and at least some of this variation is inherited
• Individuals must compete with each other for access to resources (mates, food etc), and those who survive this competition and go on to reproduce will tend to have adaptive behaviours that are more likely to lead to survival and reproductive success than those who don’t survive the competition