The Biological Approach Flashcards
What is the biological approach
Views humans as being biological organisms and provides biological explanations of all aspects of psychological functioning
- the mind lives in the brain -all thoughts feelings and behaviour ultimate have a biological basis
Influence of genes and the genetic basis of behaviour - mechanisms of heredity
Passing on characteristics from one generation to the next through genes
- why offspring take after their parents in terms of psychological characteristics
Twin studies
Used to determine the likelihood that certain traits have a genetic basis by comparing the concordance rates in a pair of twins
Concordance rate - extend to which both twins share the same characteristic
Monozygotic and dizygotic
If Identical (MZ) twins are found to have a higher concordance rate than non identical (DZ) twins it would suggest a genetic basis as MZ twins share 100% of genes whereas DZ share 50%
Disorders and concordance rates - DZ higher but not 100% - some environmental effect
Schizophrenia - Gottesman
MZ- 48% DZ- 17%
Bipolar depression - Craddock + Jones
MZ- 40%. DZ- 5-10%
Anorexia nervosa- Walters + Kendler
MZ- 23% DZ- 9%
Genes
Genes carry instructions for a particular characteristic (intelligence,temperament) but how this develops depends partly on the interaction of the gene with other genes and partly on the influence of the environment
-nature/nurture debate - extent to which a psychological character is determined by genes/environment
Genotype
Genetic code that is ‘written’ in DNA of an individual’s cells
Phenotype
The behaviour and physical structure of an individual arising from interaction between their genotype and their environment
Eg a physical characteristic such as height - the genotype dictates the maximum height an individual can reach but environmental factors such as nutrition will effect how likely this is
What is Evolution
Changes in inherited characteristics in a biological population over successive generations - mechanism=natural selection
