Biological

• • neurobiology impacts on behaviour
  • Much of human behaviour has a physiological explanation for human behaviour
  • Tries to explain how we think, feel and behave in terms of physical factors within the body
  • Evolutionary psychology considers genetic influences in common behaviours
  • From perspective - the mind lives in the brain - waning that all thoughts, feelings nad behaviour ultimately have a physical basis.
• Genetic study of the genetic make-up o organisms and how this inferences physical and behavioural characteristics
• Studies

  Twins = used to determine likelihood that certain traits have a genetic basis by comparing the concordance rates between pairs of twins - the extent to which both twins share the same characteristic 

  MZ = monozygotic twins = 100% same genes - identical

  DZ = dizygotic twins = 50% same genes - non-identical

  If MZ twins have a higher concordance rates than DZ twins then findings would suggests a genetic basis 
• Different methods for investigating genetic basis of behaviour

  • family studies
  • Twin studies 
  • Adoption studies
  • Selective breeding
• Charles Darwin


  Proposed the theory of evolution
• Theory of Evolution

  • States that human beings have evolved over millions of years
  • What we have evolved over time is genes
• Genes


  Units of inheritance that are passed on to future generations through sexual reproduction
• Genes

  • Found in nucleus of each cell in the body
  • Exist in pairs located on pairs of chromosomes - 46 chromosomes arranged in 23 pairs
  • Determine physical and psychological characteristics
• Darwin's theory of evolution

  Influenced the branch of evolutionary psychology which attempts to explain behaviour in terms of how people adapt to their changing environment
• Evolutionary psychology

  Argues that genes are responsible for physical and psychological characteristics
• Natural Selection

  • Innate behaviours, capacities that have helped us to survive and have thus been passed down
  • Animals with particular traits that provide then with an advantage are more likely to survive and reproduce there passing on their ‘adaptive traits’ to their offspring.
  • Behaviours need to adopt to the environment that the animal is living in.
• • Scientific approach, suggests that we can find cause and effect relationships of both physiology and behaviour
  • Therefore, lends credence to study of psychology - establishes psychology as a respectable science
  • Impact of biology on behaviour can lead to treatment and intervention to those suffering
• • Understanding how an abnormal brain works can shed light on normal brain functioning
  • Measurements can be objective as it can be performed by machines which have no vested interest in he outcome - PET scans, EEGs. Use of complex machinery allows accurate and precise measurements
  • Research support
• One area that has been extensively research within a biological/evolutionary perspective is that of human mating or sexual preferences.

  Buss ( 1994 ) studied attitude is and behaviours of men and women across 37 different cultures towards sexual behaviour 
• Buss ( 1994 ) - Found that men are more interested in causal sex, prefer younger partners and get more jealous over sexual infidelity on part of the woman

  To contrast, women prefer older partners, are less upset by sexual infidelity but more upset by a man becoming emotionally involved with another woman.
• Buss attributes these differences to mating preferences that have evolved in response to the reproductive demands placed on men with providing for the family
• Although traditional pattern dramatically changed in more westernised societies, evolutionary theory explains the male concern with sexual infidelity by the female partner as to do with concern over the paternity of offspring.
• • Deterministic approach as it believes that we are determined by our physiological, genetic or evolutionary make-up, thus stating that there is no free will.
  • Reductionist by stating that all human behaviour can be explained through biological processes and we are therefore not unique as individuals, also dehumanising to present humans as ‘biological machines’
• • Research may focus on on rare conditions that have little impact on the everyday lives of most people
  • Complex machinery operated by human sand therefore measurements could be subject to human error
  • Correlations frequently employed so cannot determine cause and effect
  • Small or restricted samples make findings difficult to generalise
  • Lab experiments lack ecological validity