The Biological approachSummary:

Human behaviour can be explained and understood at the level of functioning of biological systems

Biology refers to the study of living organisms (Bio- Greek for ‘living’). The biological approach aims to explain all human behaviour and experience in terms of physical bodily processes. For example; when you feel stressed, this is accompanied by sensations such as heart pounding, your palms sweating and so on. These are physical symptoms created by the activation of your nervous system. Your entire experience of stress is caused by biological processes!

Included within the biological approach are the following:*Physiological psychology, which is concerned with the functioning of the body.*The nativist approach, which is concerned with an individual’s genetic nature.*The medical approach, a term used to describe how mental disorders are explained in the same way that the medical profession explains physical illnesses.All three of these fall under the umbrella term biological approach and can, and are, sometimes used instead of the biological approach.

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The first assumption of the biological approach is that behaviour can be explained in terms of different areas of the brain. Many different areas of the human brain have been identified as specialised for certain functions. The brain is actually made of many parts, but the main part we can see is the big grey wrinkled (or folded) part covering the surface; this is called the cerebral cortex. This is the region of the brain that houses the ‘higher cognitive functions’. It is then divided into four lobes, each with specialised jobs. Underneath the cortex are the subcortical structures, and these too all have jobs governing human behaviour.

Research task:Find out the function of the following parts of the brain:

Frontal lobeOccipital lobeParietal lobeTemporal lobeCorpus callosumBrain stemSpinal cord

HippocampusHypothalamusThalamusCerebellumAmygdalaPineal glandPituitary gland

The second assumption of the biological approach, sometimes called the nativist approach, is that human behaviour can also be explained or understood at a genetic level.

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Much like certain genetic physical characteristics can be inherited from your biological parents; the biological approach applies this same idea to behaviour. i.e. some behaviours can be inherited from your parents. Task:What are some of the physical characteristics people can inherit from their parents?Are there any other characteristics you can think of that some people believe are inherited?

Some characteristics are determined by one gene (e.g. eye colour), whereas for most characteristics (e.g. intelligence), many genes are involved. Biological psychologists mostly agree that genes actually contribute to a predisposition to behave in a certain manner, rather than determining behaviour. This means a person does not necessarily behave in a certain way just because they have the genes, but it is instead a complicated relationship involving their interaction with their environment and their life experiences. An example of this would be mental illness: Not everyone who has relatives who have depression will develop depression themselves.The third assumption is that human behaviour can be explained in terms of chemicals in the body; specifically hormones and neurotransmitters. Task:

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Think how some of the following chemicals (drugs) affect people’s behaviour:CaffeineAlcoholHeroinMarijuana

CocaineEcstasyLSDMethamphetamine

Technically a chemical is any substance that has an effect on living cells. Because this could mean literally anything, including water; psychologists are somewhat more restrictive in their terminology. The study of the effects of drugs on human behaviour is an entire branch of biological psychology called psychopharmacology. We already know that foreign substances introduced to the body will have an effect on that person’s behaviour. However, biological psychologists are also very interested in the effects of substances that are native to the human body. Hormones are biochemical substances that are produced in one part of the body and circulate in the blood, having an effect on a target organ(s). They are naturally produced in very large quantities, but can disappear very quickly. Their affects can be slow, when compared with other bodily functions, but their affects are very powerful.

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Examples of hormones include; testosterone (the male hormone), oestrogen (the female hormone) and adrenalin (the stress hormone).

Task:List some of the hormones in the human body, and their effects (both physical and behavioural).

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Neurotransmitters are also biochemicals in the human body that can have an effect on human behaviour. The human body is a remarkably complex system; composed of trillions of individual cells, many with specialised jobs and nothing else (e.g. only stomach cells produce digestive secretions, only heart cells beat at a steady rhythm).

Coordinating the activity of the body’s many systems requires communication, which is one of the key functions of the specialised cells that make up the nervous system. These cells are called nerve cells, or neurons. The body depends on these cells being able to communicate quickly with one another (far quicker than hormones would ever be able to!).

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Neurons are electrically excitable cells. They have many branches at the end of each one (called dendrites) so that each neuron can communicate with many others. Each neuron communicates with another at a synapse, where their signal is relayed by the release of a chemical (a neurotransmitter). These neurotransmitters are released from presynaptic vesicles in one neuron and will either stimulate or inhibit receptors in the next neuron. The synaptic gap between each neuron is about 20nm (nanometers) wide.

Different neurotransmitters have different effects.

Some common neurotransmitters are: dopamine, serotonin, adrenaline and GABA. Research Task:

Find out the effects of each of these neurotransmitters (too much or too little).The fourth assumption of the biological approach is that psychological problems can be treated in the same way as physical disorders.

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The medical model of mental illness assumes that all mental disorders have a physical cause. It also assumes that mental illnesses can be described in terms of clusters of symptoms; and symptoms can be identified, leading to the diagnosis of an illness. The various symptoms, and the mental illnesses they may indicate, are listed in a book called the Diagnostic Statistical Manual (DSM). Every decade or so, it gets updated as new mental illnesses are ‘discovered’ or ‘disproven’. We are currently up the DSM-5. Following successful diagnosis, this can lead to appropriate physical treatments (e.g. chemotherapy)

Task:Can you name any mental illnesses?

Can you name any drugs that are prescribed to people with mental illnesses?Do you know how this drug helps with their illness?

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Strengths of the biological approach

The biological approach has proved valuable in terms of the use of chemotherapy to treat various mental disorders (schizophrenia, depression etc.) In addition genetic counselling for prospective parents is a result of our current understanding of the links between genes and behaviour. For some parents this is an enormous relief where, for example, they carry a genetic susceptibility for a fatal disease. However genetic counselling raises many ethical problems in relation to the concept of designer babies.

Explanations within the biological approach are reductionist, but this is not a bad thing, as these biological explanations have often proved useful. Examples include; the activation-synthesis theory of dreaming, and theories of schizophrenia which emphasise brain structure and/or

brain chemistry.

The biological approach has proved successful in showing that genetic factors play a role in explaining individual differences in intelligence (and in explaining why some individuals are more likely than others to develop certain mental disorders)

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Weaknesses of the biological approach

The reductionist nature of the biological approach means it is oversimplified. We can’t obtain a complete

understanding of human behaviour just by focusing only on biological factors. For example, various psychological, social and cultural factors influence the development of mental disorders such as depression and anxiety, and these factors are ignored within the biological approach.

Biological explanations are more appropriate for some kinds of behaviour (eg: vision) than other kinds of where higher order thinking is involved (eg: emotion, reasoning)

Biological explanations are deterministic, and often involve focussing on genetic factors. However, the influence of genetic factors on behaviour is typically quite indirect. For example, Plomin et al (1990) found in a twin study that genetic factors influence television watching, but it is very difficult to work out exactly how genes have this effect.

The biological approach exaggerates the importance of genetic factors in determining behaviour while minimising the importance of environmental factors.

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The way biological research is conducted means that only a few individuals are studied, and it is assumed that everyone’s biological systems work in much the same way. In fact, research on biological systems has tended to use male rather than female participants. The reason being that female hormone cycles may interfere with the biological research. Such a bias could however produce a rather erroneous picture of behaviour: one with a male bias.

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MethodologySome researchers use several different methods. Some researchers use physiological measures to increase our understanding of human behaviour. For example, the use of EEG provided evidence for different stages of sleep and showed that there is an association between dreaming and REM sleep.

A common way of assessing the importance of genetic factors is by studying identical and fraternal twins. If identical twins are more similar than fraternal twins in behaviour, this supports the notion that genetic factors are important.

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Advocates of the medical model approach to mental disorders carry out research in which they compare patients with some mental disorder with ‘normal’ individuals in order to see whether there are any significant differences in bodily functioning or structures. For example the brain volume of schizophrenics is less than that of normal controls and schizophrenics also have enlarged ventricles in the brain. Biological psychologists would also use case studies to support their theories of what each brain structures role is. The best way of finding out what each part of the brain does is to find someone who doesn’t have it, and find out what they can’t do. We can then logically assume that what they are now unable to do is what that part of their brain was for. Ethically, it would be extremely wrong to start performing surgery on people just to find out what parts of their brain do, they have to rely on people who have suffered brain damage through accidents. There are many famous case studies in psychology. These include; Clive Wearing, Phineas Gage, and David Reimer.End of approach Task

1) Outline the biological approach and give 2 strengths and 2 weaknesses of this approach.

2) Describe the methodology used in the biological approach.

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