Approaches: The biological approach

Question 1

What is the biological approach?

Answer 1

Views humans as biological organisms and so provides biological explanations for all aspects of psychological functioning.

Question 2

What are the assumptions of the biological approach?

Answer 2

Everything psychological is believed to be first biological. To understand human behaviour we need to look at genes, neurochemistry and biological structures.

Question 3

What are genes?

Answer 3

A part of a chromosome of an organism that carries information in the form of DNA.

Question 4

How are the gene mechanisms of heredity?

Answer 4

Heredity is the passing of physical and mental characteristics from one generation to the next through genes. This is why offspring take after their parents in terms of psychological characteristics.

Question 5

What is a genotype?

Answer 5

The genetic makeup of an individual. the genotype is a collection of inherited genetic material that is passed from one generation to another.

Question 6

What is a phenotype?

Answer 6

The observable characteristics of an individual. This is a consequence of the interaction of the genotype with the environment.

Question 7

What is the role of evolution for a biological psychologist?

Answer 7

Certain behaviours are very common because they are left over from processes that previously gave us a survival advantage in our early evolutionary environment e.g. certain phobias, preference for fatty/sugary food, and as a result have been passed down through the generations.

Question 8

What is natural selection?

Answer 8

The process by which inherited characteristics that enhance an individuals reproductive success are passed on to the next generation, so become more widespread in the population over time.

Question 9

How do twin studies provide evidence for the biological approach to explaining behaviour?

Answer 9

Higher concordance rates in MZ than DZ twins suggest increased similarity must be a result of the increase in shared genetics ( 100 % for MZ, 50 % for DZ ) given that it is assumed pairs of twins are raised in the same environments.

Question 10

What is a concordance rate?

Answer 10

A measure of genetic similarity- the rate of probability that two people will show the same characteristic/behaviour.

Question 11

What is a major problem for the biological approach caused by results of twin studies?

Answer 11

We never get 100% concordance which suggests that genes alone can never explain a particular illness/behaviour.

Question 12

As well as using twin studies what other concordance rates can psychologists examine?

Answer 12

Adopted children with the biological parents - different levels of relation eg: parents, aunts, uncles etc.

Question 13

What is the nervous system compromised of?

Answer 13

• The central nervous system (CNS) is compromised of the brain and spinal cord.
• The peripheral nervous system (PNS) compromised of the somatic and autonomic nervous system.

Question 14

What is the role of the nervous system?

Answer 14

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 eating are under neuronal control including breathing eating and sexual behaviour.

Question 15

How does the brain influence behaviour?

Answer 15

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 it’s called the cerebral cortex which is responsible for many high-order functions such as thought and language. The cerebrum is divided into 2 halves (known as two hemispheres), with each hemisphere further divided up into four parts known as lobes.

Question 16

What are the 4 parts of the brain and what are they responsible for?

Answer 16

Frontal lobes: Involved with functions such as speech, thought and learning.

Temporal lobes: Are involved with hearing and memory.

Parietal lobes: Processes sensory information such as touch, temperature and pain.

Occipital lobes: Processes visual information.

Question 17

How do hormones influence behaviour?

Answer 17

Hormones are chemicals that are produced in the endocrine gland such as the pituitary gland, which together makes up the endocrine system. In response to signals from the brain, hormones are secreted directly into the bloodstream by the endocrine gland but they travel to their target cells and exert their influence by stimulating receptors on the surface of or inside cells. The presence of a hormone causes a physiological reaction in the cell altering its activity.

For example, Carre et al 2006 studied a Canadian ice hockey team over the course of the season. They found evidence of a surge in levels of the hormone testosterone whenever the team played in their home stadium suggesting the hormone energises the place to defend their home territory.

Question 18

What is neurochemistry?

Answer 18

The study of chemical and neural processes associated with the nervous system.

Question 19

What is a neuron?

Answer 19

Neurons are separated by small gaps called synapses, and synaptic transmission is the process of sending information from one neuron to another.

Question 20

What is the influence of neurochemistry on behaviour?

Answer 20

The gap between two neurons is called the synaptic cleft. When the electrical signal within a neuron reaches the axon terminal of that neuron, it causes the release of neurotransmitters that cross over the synaptic cleft and are taken up by receptors in the dendrites of the other neuron. Whereas signals within neurons are transmitted electrically, signals between neurons are transmitted chemically. In other words, neurotransmitters are chemicals. When a neurotransmitter is taken up by the receptor of the next neuron, it is converted back to an electrical signal which passes along the axon of that neuron until it reaches the axon terminal where the chain can continue.

Neurons contain many different types of neurotransmitters such as serotonin, dopamine, glutamate, GABA, and acetylcholine. These different neurotransmitters can have either excitatory or inhibitory effects:

Excitatory: Increase the likelihood of the neuron firing
Inhibitory: Decrease the likelihood of the neuron firing

For example, serotonin has a generally inhibitory effect. When serotonin binds to the receptor of a neuron, it increases the negative charge of that neuron, making it less likely to fire. In contrast, glutamate has an excitatory effect. So, if glutamate outweighs serotonin in a neuron, the net effect is increased likelihood of that neuron firing.

Question 21

A03: The biological approach

Answer 21

+ Practical applications
+ The importance of the scientific method
- Reductionist approach
- Conflicting evidence

Question 22

A03: Practical applications

Answer 22

The strength of the biological approach is that it provides clear predictions e.g. about the effects of neurotransmitters on behaviour or the influence of biological rhythms on behaviour. This has led to significant applications of biological research in the real world. Research into the role of neurochemical imbalances in depression has led to the development of effective drug treatment. Likewise, research into circadian rhythms and their effect on psychological well-being has led to significant improvement in the working conditions of shift workers. This further demonstrates the value of adopting a biological approach to the study of human behaviour.

Question 23

A03: The importance of scientific method

Answer 23

The biological approach uses the scientific method, particularly the experimental method as its main method of investigation. Experimental studies take place in a highly controlled environment so that other research is able to fabricate research studies under the same experimental conditions, adding to the validity of the original findings if they can be reproduced. The use of sophisticated imaging and recording techniques has increased to precision and objectivity of experimental research in this area stop as a result these techniques have contributed to the scientific validity of the biological approach.

Question 24

A03: Reductionist

Answer 24

The biological approach is criticised for believing that complex behaviour can be broken down into the actions of genes, neurochemicals, and hormones. For example, many explanations of mental disorders are reductionist because genes or neurochemical imbalances are believed to be the main cause of these disorders. However, while a reductionist approach lends itself to scientific investigation, we cannot fully understand behaviour without also taking into account other factors that influence it. These include cognitive, emotional, and cultural factors, all of which significantly influence behaviour.

Question 25

A03: Conflicting evidence

Answer 25

Despite high concordance rates for certain behaviours and psychological disorders among identical twins (see supporting evidence above), these concordance rates are much lower than 100%. For example, Nestadt et al. (2010) examined previous twin studies in relation to OCD. Nestadt found an average concordance rate of 68% in MZ twins and a 31% concordance rate in DZ twins, highlighting a significant genetic component. These results do provide evidence of a strong genetic component, as the concordance rate MZ (68%) twin is significantly higher than the DZ twins (31%), which suggests that behaviour is partly attributed to nature because MZ twins share 100% genetic relatedness. However, the results also highlight the role of nurture as the concordance rate is not 100%, again highlighting the importance of taking an interactionist approach. This suggests there are other factors besides genetics needed to fully explain behaviour.