biological approach

• what are the main assumptions of the biological approach?

  • everything psychological is at first biological
  • biological processes/structures within the body impact behaviour
  • much of human behaviour has a psychological cause which may be genetically or environmentally altered
  • genes affect behaviour and influence psychological differences
  • psychologists should study the brain, nervous system and other biological systems - (for example; hormones)
  • the mind lives in the brain
• what are the four methods of investigation under the biological approach?

  twin studies

  adoption studies

  family studies

  selective breeding
• monozygotic twins (MZ twins)...

  are twins formed when one zygote splits and forms two separate embryos
• dizygotic twins (DZ twins)...

  are twins formed from two zygotes - two separate eggs both become fertilised from separate sperm cells
• concordance rates...

  refers to the extent to which a pair of twins share similar characteristics/traits

  • there is not a 100% concordance rate with MZ twins if a particular characteristic is a genetic one
  • DZ twins have lower concordance rates
  • comparisons can be made between twins that have grown up together and those who have been raised apart
• galton (1869)...

  believed that "all natural abilities are inherited" - however, had to later agree that any resemblance between relatives could be either a result of genes or the natural environment
• what do adoption studies involve?

  comparing a trait/characteristic between adopted children and either their adopted or biological parents
• selective breeding...

  involves artificially selecting male/female animals for a particular trait - these animals are then put together to be bred and produce offspring
• genotype...

  the actual set of genes that an individual has

  genetic material is made up of DNA

  genes only determine the potential for characteristics
• phenotype...

  an individual's observable characteristics/anatomical features

  examples = shape, metabolic activities, colour

  these attributes determine an individual's ability to reproduce/survive in the wild

  dependent on the interaction of genetic and environmental factors
• what is the biggest difference between genotype and phenotype?

  an individual's genotype is their genetic programming

  phenotype is determined by genotype

  genotype + environment = phenotype
• recessive...

  gene only shows if an individual has two of the same recessive gene

  example = bb
• dominant...

  gene always shows, even if the individual only has one copy

  example = BB, Bb
• what are some evaluation points for the biological approach?

  very scientific - uses a range of scientific techniques such as FMRI scans and twin studies

  real-life application - increased understanding of biochemical processes in the brain has led to the development of psychoactive drugs
• is the biological approach deterministic?

  yes
• how is the biological approach deterministic?

  argues that human behaviour is governed by internal, biological causes that we have no control over