the biological approach A01

• -          The biological approach view behaviour as being influenced by physical, physiological processes such as genetics, hormones, neurotransmitters and the structure of the brain.

  -          which is why biological psychologists are particularly interested in the genetic basis of behaviour showing how some characterises can be passed from generation to generation through genes.

  -          biological phycologists have also studied the important role that chemical changes in the nervous system and hormonal changes have.
• biological influences on behaviour

  the influence of genes on behaviour
• the influence of genes on behaviour

  -          genes are the mechanisms of heredity which passes on characteristics from one generation to the next through genes which explains why offspring take after there parents in terms of psychological characteristics.
• the influence of genes on behaviour

  -          genes carry instructions for particular characteristics such as intelligence or temperament but how these inherited characteristics develop is partly dependant on an individual’s interaction of the gene with other genes alongside the influence of the environment.

  -          the extent to which a psychological characteristic is determined by genes or environment is called the nature – nurture debate.
• Genotype and phenotype

  -          There is an important difference between genotypes and phenotypes
• Genotype and phenotype

  • -           Genotypes is in the genetic code that is written in the DNA of an individual’s cells. And the biological approach suggest that this genetic makeup may be the basis of certain behaviours
  • phenotype – are the observable characteristics of an individual which are a consequence of the interaction of the genotype with the environment.
• Genotype and phenotype

  -          from the beginning of conception genes begin to integrate with the environment initially this is the internal environment so the fluid within each cell and its adjacent cells, the maternal exposure to toxins and disease will also influence the internal environment of a baby . but after a child is born the external environment also interacts with the with the genotype and the characteristics, they eventually express are a result of these interactions which are the phenotypes
• Genotype and phenotype

  -          features of the phenotype change because of experience.
• The genetic bias of behaviour

  -          genes carry the instructions for particular characterises like intelligence, but each individual possesses a unique combination of genetic instructions therefore we will all differ from each other in terms of personality, intelligence, abilities – all are behaviour is different. As the outcome of how a characteristic develops is a result of how this gene interacts with other genes and the influence of the environment not all genes are turned on and whether they are or not can be influenced by an individual’s environment
• The genetic bias of behaviour

  -          The term heritability refers to the amount of variability in a trait within a population that can be attributed to genetic differences between individuals within that population and the more that a trait is influenced by genetic factors the greater its heritability, for example studies of identical twins have suggested that the variation in individuals’ intelligence could be 60-80% to do with genes.
• The genetic bias of behaviour

  -          Twin studied have been used to determine the likelihood that retain traits have a genetic bias by comparing the concordance rates between the pair of twins (the concordance rate is the extent to which bot twins share the same characteristics.
• The genetic bias of behaviour

  -          If identical twins are monozygotic it means they are twins that are found to have a higher concordance rate then non identical twins refer to as dizygotic and this would suggest that there is a genetic bias and this is because identical twins are 100% of their genes while non identical twins share only 50 % - EG – Miguel et all 2005 found a 53-87% concordance rate for identical twins and 22-47% for non-identical twins for OCD
• The genetic bias of behaviour

  -          for example, studies of identical twins have suggested that the variation in individuals’ intelligence could be 60-80% to do with genes.
• The influence of biological structures on behaviour

  Neurons and the nervous system

  -          The nervous system is compromised of several connected systems including the central nervous system which is comprises the brain and spinal cord and the peripheral nervous system which comprises the somatic and autonomic nervous system.
• The influence of biological structures on behaviour

  Neurons and the nervous system

  -          The nervous system as a whole carries messages from one part of the body to another using individual nerve cells known as neurons which transmit nerve impulses in the form of electrical signals.

  -          Many aspects of our behaviour are under neuronal control including breathing, eating and sexual behaviour.
• The influence of biological structures on behaviour

  The brain

  -          The brain and its largest part of the brain the cerebrum which makes up about 85% of the total mass of the brain.

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• The influence of biological structures on behaviour

  The brain

  -          The outer surface of the cerebrum is called the cerebral cortex which is responsible for many of the higher order functions such as thought and language.
• The influence of biological structures on behaviour

  The brain

  -          The cerebrum is also dived into two parts known as the two hemispheres and each of these hemispheres can be divided further into different parts known as lobes.
• Areas of the brain and their processes and the behaviour it influences.

  -          Broca and Wernicke area are responsible for language.
• Areas of the brain and their processes and the behaviour it influences.

  -          The hippocampus is responsible for memory.
• Areas of the brain and their processes and the behaviour it influences.

  -          Prefrontal cortex is responsible for our declarative long term memory.
• Areas of the brain and their processes and the behaviour it influences.

  -          OFC responsible for OCD behaviour

  -          Ventral striatum is linked to the behaviour of schizophrenia.

  -          Amygdala is linked to aggressive behaviour.
• Evolution and behaviour

  More recently psychologists have become interested in ideas about biological evolution and how it might be applied to human behaviour which allows us to understand the original adaptive significance of behaviours such as mate selection and aggression.

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• Evolution and behaviour

  -          Charles Darwin argued that over time organisms become adapted to their environment through biological evolution.
• Evolution and behaviour

  -          The mechanism behind biological evolution is natural selection – the process by which inherited characteristics that are enhance an individual’s reproductive successes are passed on to the next generation and so become more widespread in the population over time.

  -          This element of competition in natural selection can be seen as aggressive behaviour and the use of mate retention strategies that males may use to prevent their partners from infidelity and thus ensue it is their genes in the offspring.
• The influence of neurochemistry on behaviour

  Neurotransmitters

  -          When a nerve impulse reaches the end of one neuron a chemical called a neurotransmitter is released and it travels from one neuron to the next across the junction between them called the synapse
• The influence of neurochemistry on behaviour

  Neurotransmitters

  -          There are many different types of neurotransmitters some which trigger the receiving neuron to send an impulse, and some stop it from doing so.
• The influence of neurochemistry on behaviour

  Neurotransmitters

  -          Neurotransmitters that trigger nerve impulses in the receiving neuron and stimulate the brain into action re called excitatory neurotransmitters.

  Dopamine is an excitatory neurotransmitter that is associated with our drive or motivation.
• The influence of neurochemistry on behaviour

  Neurotransmitters

  -          Those neurotransmitters that inhabit nerve impulses and do not activate action in the brain but instead work to clam the brain and balance mood are called inhibitory neurotransmitters.

  Serotonin is inhibitory.
• The influence of neurochemistry on behaviour

  Neurotransmitters

  -          neurotransmitter which only activated the adequate amounts of which is necessary to maintain a stable mood crockett et al in 2008 found that when serotonin levels are low people tend to display increased aggression.
• The influence of neurochemistry on behaviour

  Hormones

  -          Hormones are chemicals that are produced by endocrine glands such as the pituitary gland which all together make up the endocrine system.
• The influence of neurochemistry on behaviour- hormones

  -          In a response to signals from the brain hormones are secreted directly into the bloodstream by the endocrine glands where they travel to their target cells and exert their influence by stimulating receptor on the surface of the cell or inside of it.
• The influence of neurochemistry on behaviour- hormones

  The presence of a hormone causes a physiological reaction in the cell which alters its activity for example carre et al in 2006 studied a Canadian ice hockey team over the course of a season and they found evidence of a surge in the levels of the hormone testosterone whenever the team played in their home stadium which suggests that hormones energised the players to defend their home territory