biological approach

• Our genetic inheritance comes from our parents (50%

  of our mother’s genes and 50% of our father’s). This

  explains why we may share both physical and

  psychological characteristics with our parents.
• However, although genes contain the blueprint for

  particular characteristics, how they develop or are

  expressed in a particular individual depends on the

  complex interaction between nature and nurture.
• The passing of characteristics from one generation to

  the next through genes is called Heredity.
• Genes carry the instructions for a particular

  characteristic such as intelligence or temperament

  which is innate (e.g. naturally shy personality).
• The interaction of the gene with other genes will

  determine how the characteristic develops.
• Genotype: The genetic makeup of an

  individual. This is inherited and passed

  on from one generation to the next.
• Phenotype: The observable

  characteristics of an individual. This is a

  consequence of the interaction of the

  genotype with the environment.
• Biological approach

  To understand the causes of human

  behaviour, this approach focuses on

  biological structures and processes

  such as genes, neurochemistry and the

  nervous system.
• 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.
• the more that a trait is influenced by genetic

  factors, the greater its heritability.
• The more a trait is influenced by environmental factors, the

  lower its heritability.
• The central nervous system (CNS) consists of the brain

  and spinal cord
• The peripheral nervous system (PNS) consists of the

  somatic and autonomic nervous system.
• The nervous system is split into two parts:
• The nervous system uses cells called neurons to send

  messages within the brain or from the brain/spinal cord to different parts of the body.
• Information is transmitted from one neuron to the next via electrical impulses. Many aspects of behaviour are under neuronal control, including breathing, eating and sexual behaviour.
• frontal lobe

  • thinking
  • memory
  • behaviour
  • movement
• temporal lobe

  • hearing
  • learning
  • feelings
• brain stem

  • breathing
  • heart rate
  • temperature
• parietal lobe

  • language
  • touch
• occipital lobe

  • sight
• cerebellum

  • balance
  • coordination
• six parts of the brain:

  • frontal lobe
  • temporal lobe
  • brain stem
  • occipital lobe
  • cerebellum
  • parietal lobe
• Neurotransmitters are the chemicals released when a nerve impulse reaches the end of one neuron. It travels from one neuron to the next across a junction called a synapse. They are like messengers, sending messages from one neuron to another.
• Excitatory neurotransmitters - they trigger nerve impulses

  in the receiving neuron and stimulate the brain into action, get it started. E.g. Dopamine which is associated with motivation
• Inhibitory neurotransmitters - they inhibit nerve impulses

  in order to calm the brain and balance mood, stop things. E.g. Serotonin which helps maintain a stable mood.
• Hormones are chemicals that are produced by endocrine glands such as the pituitary gland (which is in the brain).
• When a signal is received from the brain, hormones are secreted directly into the bloodstream, where they travel to their ‘target cells’ and exert their influence by stimulating receptors on the surface of or inside cells.
• The presence of a hormone causes physiological reaction in the cell,

  altering its activity.
• Evolution

  Refers to changes over successive

  generations in the genetic makeup of a

  particular population e.g. through natural

  selection (where organisms better adapted

  to their environment are more likely to

  survive and reproduce, passing on their

  genes).