The Biological Approach - The role of genetics
- Created by: hysteriababy
- Created on: 04-05-16 20:49
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- The Biological Approach - The role of genetics
- 3 basic assumptions - behaviour explained by hormones, genetics, evolution + the nervous system.
- Genetics
- Conception - egg + sperm join to give 46 chromosomes. Each is made up of coil of DNA which is made up of genes.
- Darwin's theory of evolution - over time individuals who were better adapted to their environment had better genes = more likely to survive + reproduce, passing on useful genes.
- Those less well-adapted = less likely to survive to reproduce + pass on genes. = less useful genes eliminated from gene pool.
- Natural selection = humans became better adapted to environment.
- Behaviours (phobias + aggression) evolved = the survival advantage they gave.
- Darwin's theory of evolution - over time individuals who were better adapted to their environment had better genes = more likely to survive + reproduce, passing on useful genes.
- Phenotype = the characteristics that a person's genes produce.
- Genotype = genes a person has.
- Genetics can explain Psychological traits
- Faulty genes = diseases that have psychological effects.
- Conception - egg + sperm join to give 46 chromosomes. Each is made up of coil of DNA which is made up of genes.
- Twin Studies
- Identical twins share 100% of their genes
- Non- identical twins share 50% of their genes = risk of both suffering should be lower than with identical.
- Gottesman (1991) - A meta-analysis of twin studies
- Carried out meta-analysis of approx. 40 twin studies
- Results: Having identical twin with schizophrenia = 48% chance of developing it. 17% in non-identical.
- Schizophrenia has strong genetic basis.
- So may have been another factor involved = family environment? Identical treated more similarly than non.
- Meta-analysis carried out on field studies - high ecological validity.
- Results: Having identical twin with schizophrenia = 48% chance of developing it. 17% in non-identical.
- Carried out meta-analysis of approx. 40 twin studies
- Identical twins share 100% of their genes
- Adoption Studies
- Heston (1966) - Adoption study of schizophrenia
- 47 adopted children with schizophrenic mothers studied. Control group = 50 adopted children with mothers who didn't suffer from schizophrenia.
- Children followed up as adults + interviewed = given intelligence and personality tests.
- Of experimental group = 5/47 became schizophrenic. Control group = 0. 4 of experimental group = classified as borderline schizophrenic.
- Supports that schizophrenia has genetic basis.
- Interview data = unreliable + affected by social desirability bias.
- But interviews are good way of getting data in naturalistic way.
- Children whose mothers didn't suffer from any conditions may not have shown symptoms yet
- But interviews are good way of getting data in naturalistic way.
- 47 adopted children with schizophrenic mothers studied. Control group = 50 adopted children with mothers who didn't suffer from schizophrenia.
- Heston (1966) - Adoption study of schizophrenia
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