The Biological Approach: Key Assumptions
1) The biological approach is on the nature side of the nature/nurture debate.
2)The mind & the brain are the same
3) Behaviour & thought processes have an innate, biological basis
4) Behaviour & characteristics (such as intelligence) are influenced by our genetic make-up.
5) The brain & the central nervous system influence our behaviour.
6) Human genes have evolved to adapt behaviour to the environment - behaviours that help us to survive will be passed on, whereas those which dont will die out.
7) Chemical processes in the brain are responsible for our psychological functioning, an imbalance of these may lead to disorders (such as low levels of Serotonin leading to Mood disorders like depression)
Biological Approach: Research Methods
- Surgery - neurosurgery & animal experiments
- Brain recording techniques such as scans (MRI, PET, CT)
- Experiments to test the effects of drugs
- Post-mortum studies - such as Broca's 'Tan'
- Case studies - such as Phineas Gage
- Twin studies - looking for concordance rates between Monozygotic & Dizygotic twins
- Family studies - examining the similarites between different degree relative (such as the amount of schizophrenia sufferers with a parent also with the disorder)
- Selective breeding programmes - the artificial selection of mlae & female snimals for particular traits, these animals are bred & their offspring is observed to see if the trait in hereditary.
Influence of Genes: Key Terms
- Nucleus - in most cells of the body there is a nucleus, in each nucleus (apart from in sex cells) there are 46 chromosomes
- Chromosomes - made of of DNA, the DNA contains units of information called genes
- Heredity - traits, characteristic & behaviours inherited from our parents.
- Genotype - an individual's gentic make-up, the normal 23 pairs of chromosomes. Everyone has a unique genotype except monozygotic (identical) twins, who have the same
- Phenotype - the expression of the genotype (such as appearance & behavioural & psychological characteristics)
- Psychological charactistics (intelligence, aspects of personality), some psychological disorders (schizophrenia) & male & female differences (aggression) are all thought to be influences by genes.
Bock & Goode (1996)
- Conducted an animal study on mice to test whether aggression was inherited or learnt.
- Found that when reared alone the mice showed a strong tendency to attack other male mices when first exposed to other animals.
- The mice were not taught to be aggressive, they just exhibited the behaviour.
- This implies an innate, genetic tendency in relation to biological aggression.
Evolution of Behaviour
In 1859 Darwin published The Origin of Species & proposed that all living things have evolved from their ancestors through a process of natural selection.
It is the concept of 'survival of the fittest' - a species either adapts to its environment or dies out, the process of natural selection explains how the strongest genes survive & are passed on & the weaker genes die out.
The Biological Approach: Strengths & Weaknesses
- Uses scientific experimental procedures in its investigations.
- Provides a strong argument for the nature side of the nature/nurture debate
- It has had many useful applications - such as drugs that alleviate disorders like bipolar depression.
- The role of the brain in higher mental functions, such as memory, is beginning to be understood.
- Shows us how evolution & genetics influence behaviour.
- Reductionalist - reduces all thoughts & behaviours in terms of nerves or chemicals
- Over-simplistic - fails to take into account environmental or social factors that can influence thoughts & behaviour
- Raises ethical issues - such as genetic mapping