7 - The Biological Approach ( Genetics and Biological Structures) Flashcards
Outline the biological approach
Views human beings as biological organisms and so provides biological explanations of all aspects of psychological functioning.
Interested in the genetic bases of behaviour and chemical changes in the nervous system, as well as hormonal changes.
How do characteristics develop in people? How is this linked to the nature-nurture debate?
Heredity is the passing of characteristics from one generation to the next thorough genes.
Genes carry the instructions for a particular characteristic but how this characteristic develops depends partly on the interaction of this gene with other genes, and the influence of the environment.
The extent to which a psychological characteristic is determined by genes or the environment is called the nature-nurture debate.
What is the difference between genotype and phenotype?
Genotype - the genetic code that is written in the DNA of an individual’s cells
Phenotype - physical appearance that results from inherited information
Relate monozygotic twins to genotype and phenotype
They have identical genotypes, but can end up with very different phenotypes, and so behave quite differently.
This difference is caused by their different environments.
Define heritability
Refers to the extent that the variability within a trait in a population can attributed to genetic differences.
The more a trait is influenced by genetics the greater the heritability.
Outline evolution and behaviour and how it relates to the biological approach
Charles Darwin argued that over time, organisms adapt to their environment through biological evolution.
This refers to the changes that take place in the characteristics of a population over time. The mechanism behind biological evolution is natural selection.
Individuals within a species differ from each other in terms of their physical characteristics and in their behaviour. At least some of this variation is inherited. Because individuals must compete with each other for access to resources (mates, food, etc), those who survive this competition and go on to reproduce will tend to have behaviours that make them successful in the competition for resources.
These behaviours will then be passed onto their offspring and will become more widespread in the population. Through the process of natural selection, successive generations will develop behaviours that are even more likely to lead to survival and reproductive success.
What are the 3 main components of the biological approach?
Genetics, Evolution, Biological structures
What does the nervous system comprise of?
The central nervous system - the brain and the spinal cord
The peripheral nervous system - the somatic and autonomic nervous systems
What is the function of the nervous system?
Carries messages from one part of the body to another using individual nerve cells known as neurons.
Neurons transmit nerve impulses in the form of electrical signals. Many aspects of behaviour are under neuronal control, e.g. breathing and eating.
Describe the structure of the brain
The largest part of the brain is the cerebrum (85%) of the total mass of the brain.
The outer surface is called the cerebral cortex, which is responsible for higher order functions such as thought and language.
The cerebrum is divided into two halves (known as hemispheres) with each individual hemisphere further divided into four different parts (known as lobes).
What are the positives of the biological approach?
Uses the scientific method, particularly the use of the experimental method, as its main source of investigation. Experimental studies take place in highly controlled environments so that other researchers are able to replicate research studies under the same experimental conditions, thus adding to the reliability of the research.
Provides clear predictions about a person’s behaviour. This has led to practical applications of the biological approach in the real world. For example, knowledge about the chemical imbalance in depression has led to the development of drug treatments, which correct this imbalance.
If people know they have a genetic predisposition for a mental disorder, such as schizophrenia, this gives them an opportunity to avoid environmental situations likely to trigger this predisposition or to develop coping skills that would protect them from its potential influence.
What are the limitations of the biological approach?
Reductionist. Believes that complex human behaviour can be explained by breaking it down into its smallest component parts, such as the action of genes, neurotransmitters and hormones. Argued that we cannot fully understand behaviour without taking account of all the different factors which influence it (cognitive, emotional and cultural) , all of which have a significant influence on behaviour.
Recent research suggesting a genetic basis for criminal behaviour has led to concerns about how this information could be used. It could lead to genetic screening of populations to identify genetic susceptibilities and subsequent discrimination against those with a genetic predisposition to crime.
