Biological Approach Flashcards
Assumptions of the biological approach
Everything psychological has a biological basis
Biology is determined by evolution and genetics
We must investigate the physical brain to investigate the mind
Genes
Sections of DNA that:
Code for enzymes and hormones
Code for development of characteristics
Code for production / functioning of CNS
Genes have an indirect impact on behaviour
How genes link to human behaviour
Genes lead to vulnerability of OCD
5-HTT gene = transport of serotonin
If the gene is faulty then there will be low levels of serotonin in the synapse - lead to OCD
How is the brain linked to human behaviour
Controls our day to day behaviour - emotions, thoughts, sensations
Cerebral cortex ( outer surface of cerebrum) - involved in higher mental processes
Damage to brain-impairs thinking ability-impairs behaviour
Neurotransmitters
Chemical messengers that travel back and forth in the synapse delivering messages between neurones
Can increase (excitatory) or decrease (inhibitory) the likelihood of neurones firing
Excitatory= dopamine (associated with drive / motivation)
Inhibitory = serotonin (stabilises mood)
How neurotransmitters are linked to human behaviour
Researchers found that:
High seratonin=anxiety
Low serotonin = depression
Process of evolution
Random mutation
Adaptive characteristics
Better suited to survive
Natural selection
Genetically pass on traits
Carried on for successive generations
Evolve
Strengths of biological approach
Supporting evidence for genetic explanations
Practical application of biochemical applications
Limitations of biological approach
Questionable validity of supporting evidence (nature and nurture)
Biological explanations are reductionist
Genotype
Genes an organism has inherited
Phenotype
Traits expressed in an organism
Interaction between different genes
If a dominant allele is inherited from either parent- characteristic is always expressed
A recessive allele is only expressed in phenotype if inherited from both parents
Interaction between genes and environment
Development of disorders is caused by both diathesis factors
Genetic vulnerability + Environmental stressors
Golden rule of twin studies
If concordance rate did MZ twins is double or more the rate for DZ twins, the characteristic has a genetic basis
Concordance rate
Likelihood of having a characteristic if your twin has the characteristics
