The biological approach Flashcards
The biological approach
Behavior, according to the biological approach, is a result of our genetics and physiology.
Only approach that investigates thoughts, feelings and behaviors from a biological and thus physical perspective.
The influence of genes on behaviour
Biological psychologists carry out family history studies in order to assess the influence of genes on mental disorders.
Twin studies have shown to be more precise in assessing the extent of genetic influences on behaviours.
McGiffin et al (1996) found a concordance rate of 46% in monozygotic twins, compared with 20% in dizygotic twins, in relation to depression.
Indicates that environmental factors play a role too.
The influence of neurochemistry on behaviour
Neurochemistry is the study of chemical processes that take place in the nervous system
The main focus is on synaptic neurotransmitters
Dopamine and serotonin are essential for transmission of nerve impulses across the synapse and are therefore involved in all aspects of behaviour.
Psychoactive drugs such as cocaine affect neurotransmitters. It acts at synapses, blocking the reuptake of dopamine back into the presynaptic neuron.
This temporarily increases the dopamine available in the synaptic gap, which leads to the rush of euphoria.
After a short period of time, dopamine becomes depleted and insufficient amounts are released, this leads to the characteristic low mood felt by drug users.
Disruption to neurochemistry is implicated by depression, such as imbalances in serotonin, dopamine and noradrenalin.
Treatment includes SSRI (Selective Serotonin Reuptake Inhibitors), which help to prevent the reuptake of serotonin at the synapse, making more neurotransmitters available.
The influence of biological structures on behaviour
Uses case studies on brain injury
Phineas Gage:
A metal bar passed through his skull and brain. Gage survived and showed little intellectual impairment, continuing to function relatively normally.
However, he showed significant changes to his personality/ quick tempered/ foul-mouthed
Damage occurred to the frontal lobes, indicating that these structures are responsible for behaviour.
Brain scans of of violent criminals were compared to matched controls and showed reduces activity in the frontal lobes, showing that the area is important in the control of impulsive behaviours.
Genotype and phenotype
Genotypes:
The genetic makeup of an organism/ their complete set of genes
Phenotypes:
The observable traits of an organism that result from the interaction of its genotype with the environment.
Evolution and behaviour
In relation to evolution, biological psychology makes the assumption that the biological structures and behaviours shown by modern humans exist because they brought advantages to our ancestors.
Charles Darwin found that members of species vary and those who are better equipped to find food or escape from predators, are more likely to survive and pass on their genes to the next generation.
Offsprings inherit the traits that lead to the survival advantage (natural selection).
Evaluation
Strength:
Has helped with the treatment of mental disorders. Dopamine has been linked with schizophrenia. Antipsychotics have been made to increase dopamine levels to help reduce sz symptoms.
Techniques such as brain scans have helped to identify frontal lobes as the area responsible for behaviour (Phineas Gage). Contributes to better understanding of behaviour.
Limitation:
The approach is considered reductionist; complex behaviour, thoughts and emotions are all equally explained by low-level biological mechanisms such as biochemicals and nerve impulses, neglecting the effects of childhood and our social and cultural environment.
It tends to ignore individual differences. Humans have generally have similar brain structures so this suggests that we should all have identical behaviours unless our brain is damaged.
It contradicts behaviourist and environmental research.
