Biological approach

• Behaviour is a result of - 


  -Genes

  -Neurochemistry

  -Biological structures

  -Evolution
• Genes-

  Heredity is the passing of characteristics from one generation to another through their genes. Genes may carry instructions for a particular characteristic, but how that develops may be down to the interaction with other genes or the environment. It is therefore important that we distinguish between genotype and phenotype
• Genotype- 


  Particular set of genes that a person possesses. We inherit one set of chromosomes from mother, one from father. We all have 46 chromosomes each in total
• Phenotype- 


  The characteristic of an individual determined by both genes and environment
• Genes-

  To investigate if a particular trait is inherited, researchers look to see if the trait is also found in other relatives, this is known as concordance rate.

  They may use family studies, twin studies (compare monozygotic (MZ) and dizygotic (DZ) twins) or adoption studies (compare concordance with biological vs adoptive families)
• Example study- Genes

  -Nestadt et al (2000) concluded that OCD has a genetic component, first degree relatives (siblings, children) of OCD sufferers have a 11.7% chance of developing OCD compared with 2.7% risk in general population

  -There is now research being conducted on the warrior gene (MAOA) which is found in 1/3 of men. This gene seems to be linked to risk taking behaviour and aggression.
• Strength of genes- 


  -Supporting study was conducted by Hyde et al (2009). They studied the brains of 6 year olds who had received 14 months of instrumental musical training.

  -This training produced significant changes in primary auditory and primary motor areas of the brain.

  -Therefore, demonstrating the distinction between genotype and phenotype.

  -In this case the training (environment) altered the phenotype.
• Limitation of genes- (twin and family studies) 


  -It is impossible to separate the impact of environment from genetics.

  -In twin studies monozygotic twins may be treated in a more similar way than dizygotic, which may account for the increase in concordance rates.

  -Unless a concordance rate for MZ twins is 100%, you cannot conclude that the development of a certain characteristics is solely due to genetics
• Neurochemistry includes neurotransmitters and hormones. There are several studies that show a link between a neurochemical imbalance and a certain behaviour or disorder. Neurotransmitters such as dopamine and serotonin are essential for transmission of nerve impulses across the synapse and therefore are involved in a wide range of behaviours
• Neurochemistry-

  Serotonin is involved in sleep, sex, memory, social behaviour, appetite to name but a few behaviours. A lack of serotonin is linked to depression, OCD and eating disorders.

  Scerbo & Raine (1993) investigated neurotransmitter levels in antisocial children and adults. They found lower levels of serotonin in individuals described as aggressive. These lower levels of serotonin were also found in people who attempted suicide however, they found no link between aggression and dopamine levels
• Neurochemistry-

  Dopamine is associated with our attention and motivation. An excess of D2 dopamine receptors is linked to the development of schizophrenia. Comer (2003) states that dopamine neurons play a key role in guiding attention, therefore distributions may well lead to the problems relating to attention, perception and thought found in people with schizophrenia
• Neurochemistry-

  The hormone testosterone is thought to be linked with aggression and territorial behaviour. Carre et al (2006) studied ice hockey players and found that their testosterone levels surged when they played at their home stadium suggesting the testosterone energised players to defend their home territory
• Strength neurochemistry- 


  -Real world applications from this research

  -Several dug therapies have been developed based upon neurotransmitter research, such as antidepressants

  -These drugs are designed to increase the levels of serotonin, by preventing its reuptake in the synapse.

  -However, we are unable to establish a causal relationship between neurotransmitters and behaviour.

  -Researchers have established an association between serotonin and depression, but we cannot say that serotonin levels of depression
• Biological Structures-

  The relationship between various parts of the brain and their functions is an important focus of the biological approach. Early work in this field progressed via case studies. One such case study was Phineas Gage who suffered damage to his brain and as a result underwent a personality change
• Biological structures-

  Certain functions of the brain can be localised to areas of the brain and damage to these areas can result in cognitive impairment, for example the role of the hippocampus in memory
• Strength biological structures -


  -Raine(1997) examined the PET scans of violent crimes and compared them with a matched control group

  -The scans of the criminals indicated a reduced activity in the frontal lobes, supporting the idea, from the case of Phineas Gage that this area is important in the control of impulsive behaviours
• Strength biological structures 


  -Woollett & Maguire (2011) looked at London taxi drivers who have to memorise 25,000 London streets as part of a test known as 'The Knowledge'.

  -Using brain scans they were able that successful applicants to this test had an enlarged hippocampus.

  -They concluded that the hippocampus is a key component of memory
• Evolution & Behaviour-

  There is a point in time known as EEA, this is when we became physically and cognitively as we are now. Certain behaviours were adaptive, that is, they served a purpose in keeping us alive and allowing us to have reproductive success. If a genetic mutation increases the chance of survival (it has been adaptive) then the mutation is passed onto next generation
• Evolution & Behaviour -

  Biological psychologists believe that intelligence and aggression were adaptive at the onset and therefore they became a part of evolutionary process.
• Evolution & Behaviour -

  For example, aggression may be adaptive as it can increase access to resources such as food and territory. This increase in resources increases the chance of survival and increases the number of mates available to that individual. Therefore, increasing the chances of reproductive success
• Evolution & Behaviour -

  Lea et al (2005) argues that the warrior gene MAOA has a genetic basis and is found in 1/3 of men. This gene is linked to impulsive and risk taking behaviour
• Evolution & Behaviour -

  Psychologists are interested in evolution of behaviour and how behaviour that we might have displayed in EEA is shown in everyday life. For example, Bowlby argued that babies are evolutionary programmed to form attachments to their primary care giver. Buss argued that we are also evolutionary programmed to seek certain characteristics in mates.
• Weakness of biological approach- 


  -It can be argued that this is too simplistic an explanation when looking at causes of mental illness

  -It ignores the influence of childhood and life events that can be a trigger for such illnesses as depression

  -Therefore, we can argue that it is a reductionist approach