Biological approach

• Biological approach argues that human are biological beings and their behaviour is explained as a result of their genetic build up and biological structures. This includes the hormonal and nervous systems. Neurochemistry, genetics and evolution are also thought to play a part in this.
• Influence of biological structures on behaviour:

  • Endocrine system is a body wide system of glands which release hormones.
  • During fight or flight, the brain signals the adrenal gland to release adrenaline. This travels through the bloodstream enhancing flow to the brain and muscles, while decreasing it to the digestive organs and skin.
  • Hormones can have long term effects on the body and behaviour. For example, sex hormones like oestrogen and testosterone play a role in developing gender-specific features. However, testosterone is associated with male traits and is linked to aggression.
• The brain is the centre of all conscious and unconscious thought:

  • Brain stem controls core physiological functions (eg heart rate and breathing).
  • Cerebellum is involved in coordinating muscle movement and balance.
  • Cerebrum has two hemispheres connected by a bundle of nerves called the corpus callosum. Each hemisphere is divided into four lobes; frontal, temporal, occipital and parietal.
  • Limbic system is the emotional centre of the brain and has structures called the amygdala, thalamus and hippocampus.
• Strengths of the brain structure in influencing behaviour:

  • Historical research - Influence of brain structures on behaviour were seen in case studies (eg 'Tan').
• Influence of genes on behaviour:

  • Genes act as a set of instructions for making the components of the cell, including the brain and influence how the cells are formed and function.
  • Genotypes are the genetic code in DNA for the characteristics of an organism. Phenotypes are the physical extension of the genotype. Biological psychologists argue the genotypes are for behaviours and phenotypes are for expression of said behaviour (eg being aggressive).
  • Diathesis-stress model.
• Influence of evolution on behaviour:

  • Darwin's theory of natural selection.
  • Evolutionary psychologists extend this to argue that behaviour is inherited providing survival advantages.
  • They suggest in the early hunter-gatherer societies, male aggression was beneficial for protecting families and competing for mates. Although high aggression is less advantageous in society today, the reason for men possessing this trait is due to inheritance.
• Strengths of the biological approach:

  • Supporting evidence - Evidence for biological structures, neurochemistry and genetic influence are backed up by scans (eg fMRI and PET scans).
  • Soomro's meta-analysis (OCD treatment - placebo effect).
• Strengths of the biological approach:

  • Practical application - Developing drug treatments for health conditions. An SSRI was created in the treatment for OCD which millions of people have benefitted from.
• Strengths of the biological approach:

  • Scientific - Use of advanced tools, such as fMRI scanners, genetic analysis and direct measurements of hormones and neurotransmitters offer direct observation. Studies are also highly controlled, providing more objective data rather than self-reports and influences, which are common in other approaches.
• Limitations of the biological approach:

  • Biological determinism - Belief that all actions are predetermined by biological factors have implications. Arguing criminal behaviour is due to a 'criminal gene' could challenge legal principles of responsibility as individuals cannot control their genes.