The biological approach: the influence of genes, biological structures and neurochemistry on behaviour. Genotype and phenotype, genetic basis of behaviour, evolution and behaviour.
Biological influences on behaviour
The influence of genes on behaviour- Genes the mechanisms of heredity, heredity is the passing of characteristics from one generation to another through the genes and is the reason why offspring take after their parents in terms of psychological characteristics. Genes carry the instructions for a particular characteristic, how this characteristic develops depends partly on the interaction with this gene and other genes.
The influence of genes on behaviour- Genes the mechanisms of heredity, heredity is the passing of characteristics from one generation to another through the genes and is the reason why offspring take after their parents in terms of psychological characteristics. Genes carry the instructions for a particular characteristic, how this characteristic develops depends partly on the interaction with this gene and other genes.
This approach views human beings as biological organisms and so provides biological explanations of all aspects of psychological functioning. Biological psychologists are particularly interested in the genetic basis of behaviour, showing how some characteristics can be passed from generation to generation through the genes.
Genes, the mechanisms of heredity.
Heredity is the passing of characteristics from one generation to the next through the genes and is the reason why offspring take after their parents in terms of psychological characteristics.
Genotype- the genetic code that is written in the DNA of an individuals cells.
Phenotype- the physical appearance that results from this inherited information.
The influence of neurochemistry on behaviour
Neurotransmitters, when a nerve impulse reaches the end of one neuron, a chemical called a neurotransmitter is released. It travels from one neuron to the next across a junction called a synapse. There are many different types of neurotransmitter, some of which trigger the receiving neuron to send an impulse and some stop it from doing so. Those ones that trigger nerve impulses in the receiving neuron and stimulate brain into action are called excitatory neurotransmitters. Those that inhibit nerve impulses in order to calm the brain and balance mood are called inhibitory neurotransmitters. Dopamine is an excitatory neurotransmitters that is associated with our drive or motivation. Serotonin is an inhibitory transmitter adequate amounts of which are required to maintain a stable mood. Crockett et al (2008) found that when serotonin levels are low people tend to display increased aggression.
Neurons and the nervous system
The nervous system is comprised of several connected systems.
the central nervous system (CNS) comprises the brain and spinal cord.
The peripheral nervous system (PNS) comprises the somatic and autonomic nervous systems.
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 electric signals. Many aspects of behaviour are under neural control, including breathing, eating and sexual behaviour.
The Brain
The largest part of the brain is the cerebrum, making up about 85% of the total mass of the brain. The outer surface of the cerebrum is called the cerebral cortex, which is responsible for many of the higher code functions such as thought and language. The cerebrum is divided into two halves known as hemispheres, with each hemisphere further divided into four different parts known as lobes.
Genes, the mechanisms of heredity.
Heredity is the passing of characteristics from one generation to the next through the genes and is the reason why offspring take after their parents in terms of psychological characteristics.
Genotype- the genetic code that is written in the DNA of an individuals cells.
Phenotype- the physical appearance that results from this inherited information.
The influence of neurochemistry on behaviour
Neurotransmitters, when a nerve impulse reaches the end of one neuron, a chemical called a neurotransmitter is released. It travels from one neuron to the next across a junction called a synapse. There are many different types of neurotransmitter, some of which trigger the receiving neuron to send an impulse and some stop it from doing so. Those ones that trigger nerve impulses in the receiving neuron and stimulate brain into action are called excitatory neurotransmitters. Those that inhibit nerve impulses in order to calm the brain and balance mood are called inhibitory neurotransmitters. Dopamine is an excitatory neurotransmitters that is associated with our drive or motivation. Serotonin is an inhibitory transmitter adequate amounts of which are required to maintain a stable mood. Crockett et al (2008) found that when serotonin levels are low people tend to display increased aggression.
Neurons and the nervous system
The nervous system is comprised of several connected systems.
the central nervous system (CNS) comprises the brain and spinal cord.
The peripheral nervous system (PNS) comprises the somatic and autonomic nervous systems.
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 electric signals. Many aspects of behaviour are under neural control, including breathing, eating and sexual behaviour.
The Brain
The largest part of the brain is the cerebrum, making up about 85% of the total mass of the brain. The outer surface of the cerebrum is called the cerebral cortex, which is responsible for many of the higher code functions such as thought and language. The cerebrum is divided into two halves known as hemispheres, with each hemisphere further divided into four different parts known as lobes.
Evaluation
Strengths - The importance of the scientific method- the biological approach uses the scientific method particularly the use of the experiment method 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 validity of the original findings if they can be reproduced. In early studies of brain functioning clinical case studies were the primary method of study but they were fraught with difficulties such as researcher bias and lack of control. However the use of sophisticated imaging and recording techniques has increased the precision and objectivity of experimental research in this area.
Applications of biological approach- it provides clear predictions which has led to significant applications of biological research in the real world. For example, research into the role of neurochemical imbalance in depression has led to the development of drug treatments which correct this imbalance and minimise depressive symptoms.
Limitations
The biological approach is reductionist- this is the belief that complex human behaviour can be explained by breaking it down into its smallest components, such as the action of genes, neurochemicals and hormones. For example many explanations of mental health are reductionist because genes or neurochemical imbalances are believed to be the main causes of these disorders. However whilst a reductionist approach lends itself to scientific investigation critics argue that we cannot fully understand a behaviour without also taking account of the emotional and cultural factors that influence it. These include cognitive, emotional and cultural factors all of which have a significant influence on behaviour.
Problems for evolutionary explanations of behaviour- because most human behaviour can be transmitted by both genetic and cultural routes, an evolutionary explanation of behaviour is complicate by this additional possibility. Critics of evolutionary explanations claim that many established patterns of human behaviour have purely cultural origins with no survival or reproductive value. An example would be the incest taboos that exist within most societies, an evolutionary explanation would emphasise the problem of genetic mutations that would arise from inbreeding: therefore natural selection would favour those individuals that avoided such practises. However most cultures also have strict culturally determined moral codes of conduct and incest taboo would undoubtedly form a part of such codes.
Strengths - The importance of the scientific method- the biological approach uses the scientific method particularly the use of the experiment method 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 validity of the original findings if they can be reproduced. In early studies of brain functioning clinical case studies were the primary method of study but they were fraught with difficulties such as researcher bias and lack of control. However the use of sophisticated imaging and recording techniques has increased the precision and objectivity of experimental research in this area.
Applications of biological approach- it provides clear predictions which has led to significant applications of biological research in the real world. For example, research into the role of neurochemical imbalance in depression has led to the development of drug treatments which correct this imbalance and minimise depressive symptoms.
Limitations
The biological approach is reductionist- this is the belief that complex human behaviour can be explained by breaking it down into its smallest components, such as the action of genes, neurochemicals and hormones. For example many explanations of mental health are reductionist because genes or neurochemical imbalances are believed to be the main causes of these disorders. However whilst a reductionist approach lends itself to scientific investigation critics argue that we cannot fully understand a behaviour without also taking account of the emotional and cultural factors that influence it. These include cognitive, emotional and cultural factors all of which have a significant influence on behaviour.
Problems for evolutionary explanations of behaviour- because most human behaviour can be transmitted by both genetic and cultural routes, an evolutionary explanation of behaviour is complicate by this additional possibility. Critics of evolutionary explanations claim that many established patterns of human behaviour have purely cultural origins with no survival or reproductive value. An example would be the incest taboos that exist within most societies, an evolutionary explanation would emphasise the problem of genetic mutations that would arise from inbreeding: therefore natural selection would favour those individuals that avoided such practises. However most cultures also have strict culturally determined moral codes of conduct and incest taboo would undoubtedly form a part of such codes.
Key Terms
Biological Approach, view humans as biological organisms and so provides biological explanations for all aspects of psychological functioning.
Evolution, Refers to the change over successive generations of the genetic make up of a particular population. The central proposition of an evolutionary perspective is that the genotype of a population is changeable rather than fixed, and that this change is likely to be caused by a process of natural selection.
Gene, A part of the chromosome of an organism that carries information in the form of DNA.
Genotype, the genetic make up of an individual. The genotype is a collection of inherited genetic material that is passed from generation to generation.
Natural Selection, The process by which inherited characteristics that enhance an individuals reproductive success (fitness) are passed onto the next generation, and so become more widespread in the population over time.
Neurochemistry, The study of chemical and neural processes associated with the nervous system.
Phenotype, The observable characteristics of an individual. This is a consequence of the interaction of the genotype with the environment.
Biological Approach, view humans as biological organisms and so provides biological explanations for all aspects of psychological functioning.
Evolution, Refers to the change over successive generations of the genetic make up of a particular population. The central proposition of an evolutionary perspective is that the genotype of a population is changeable rather than fixed, and that this change is likely to be caused by a process of natural selection.
Gene, A part of the chromosome of an organism that carries information in the form of DNA.
Genotype, the genetic make up of an individual. The genotype is a collection of inherited genetic material that is passed from generation to generation.
Natural Selection, The process by which inherited characteristics that enhance an individuals reproductive success (fitness) are passed onto the next generation, and so become more widespread in the population over time.
Neurochemistry, The study of chemical and neural processes associated with the nervous system.
Phenotype, The observable characteristics of an individual. This is a consequence of the interaction of the genotype with the environment.
Resources and Activities
Explain what is meant by genotype and phenotype.
Outline the influence of genes on behaviour.
Outline the influence of biological structures and neurochemistry on behaviour.
Explain the difference between genotype and phenotype.
Outline the relationship between evolution and behaviour.
Activities
The group gets split into four, find out about your assigned part of the brain and prepare to explain it to the class.
Group discussion lets all think about some of the genes we think we share with our families.
Debate about nature and nurture.
In pairs make an information sheet about neurotransmitters and the journey they make explaining each stage.
Exit pass- for the intro lesson this could be outline the ways in which the biological approach differs to the cognitive approach.
Explain what is meant by genotype and phenotype.
Outline the influence of genes on behaviour.
Outline the influence of biological structures and neurochemistry on behaviour.
Explain the difference between genotype and phenotype.
Outline the relationship between evolution and behaviour.
Activities
The group gets split into four, find out about your assigned part of the brain and prepare to explain it to the class.
Group discussion lets all think about some of the genes we think we share with our families.
Debate about nature and nurture.
In pairs make an information sheet about neurotransmitters and the journey they make explaining each stage.
Exit pass- for the intro lesson this could be outline the ways in which the biological approach differs to the cognitive approach.