The biological approach

• Evaluation: Biological determinism (limitation)

  The approach is determinist.

  It sees human behaviour as governed by internal, genetic causes over which we have no control.

  An individuals phenotype is heavily influenced by the environment, MZ twins who share 100% genes don't behave the same.

  Problematic for crimes, could criminals excuse their behaviour by claiming it was because of the 'crime gene'?

  The biological view is too simplistic and ignores the mediating effects of the environment.
• Evaluation: Scientific methods (strength)

  The approach uses scientific methods of investigation.

  The approach makes use of a range of precise and highly objective methods - scanning techniques, fMRI and EEGs.

  Advances in technology makes it possible to accurately measure psychological and neural processes in ways that aren't open to bias.

  This approach is based on objective and reliable data.
• Evaluation: Real-world application (strength)

  Increased understanding f neurochemical processes in the brain is associated with the use of psychoactive drugs to treat serious mental disorders.

  Eg. promoted the treatment of clinical depression using antidepressant drugs, increase levels of the neurotransmitter serotonin at synapses in the brain.

  Such drugs have been associated with the reduction of depressive symptoms.

  People with depression are better able to manage their conditions and live their lives in the community, rather than remain in the hospital.
• Natural selection

  Any genetically determined behaviour that enhances an individual's survival will continue in future generations. The possessor is more likely to survive, reproduce and pass on these traits. If the individual survives but doesn't reproduce, traits don't remain in gene - can't be passed on to future generations.
• Evolution and behaviour

  Charles Darwin proposed a theory to explain evolution - natural selection.
• Phenotype


  The characteristics of an individual determined by both genes and the environment.
• Genotype


  The particular set of genes that a person possesses.
• Genotype and phenotype


  Despite having the same genes, the way MZ twins' genes are expressed is different. Biological psychologists accept, that much of human behaviour depends upon an interaction between inherited factors (nature) and the environment (nurture).
• McGuffin et al. (1996)


  Study of 177 twins suffering from major depression Diagnostic assessments and more detailed interviews were carried out on 19 of the original twins on the register, and 75 co-twins. The interviewers didn't know whether the twin was MZ or DZ. The correlation was calculated, concordance rate for MZ twins was 46%, and 20% for DZ twins.
• Concordance rate


  The extent to which twins share the same characteristics.
• Twin studies


  Twin studies are used to investigate whether certain psychological characteristics have a genetic basis. Done by analysing concordance rates. If a characteristic is genetic then MZ twins should share 100% of genes, DZ twins share about 50% of genes.
• The genetic basis of behaviour

  Psychological characteristics (ie. intelligence) are inherited just like biological characteristics (ie. height).
• The neurochemical basis of behaviour

  Refers to the action of chemicals in the brain. Much of thoughts and behaviours rely of chemical transmission in the brain.

  Occurs using neurotransmitters, an imbalance of neurotransmitters is a possible cause of mental illness,
• Assumptions

  Everything psychological us at first biological, to understand behaviour you must look to biological structures and processes.

  The mind lives in the brain - all thoughts, feelings and behaviour have a physical basis.