Overview of Issues and Debates in Biological Psychology (Edexcel A-Level Psychology): Revision Notes
Overview of Issues and Debates in Biological Psychology
Ethics in animal research
Animal research has played a substantial role in biological psychology. Several justifications support this practice:
Practical advantages of using animals:
Animals possess simpler central nervous systems, making it easier to observe neurological processes. For example, Eric Kandel (1965) studied basic learning mechanisms in Aplysia californica (a sea slug), which has approximately 20,000 well-defined neurons compared to humans' 100 billion.
Researchers can exercise strict environmental control over non-human subjects, enabling rigorous experimental designs. Animals can be raised in isolation to eliminate socialisation effects, which would be unethical with human participants.
Invasive Research Methods
Invasive procedures can be conducted on animals that would be ethically impermissible with humans. Olds and Milner (1954) attached electrodes to various brain regions in male black-hooded rats. The rats could activate these electrodes via a lever, stimulating specific brain areas.
This research revealed a potential mechanism for addiction: rats with electrodes connected to their reward system (nucleus accumbens and ventral tegmental areas) pursued this activity at the expense of typically rewarding behaviours such as eating and sex.
Ethical concerns and counter-arguments:
Despite these practical benefits, animal rights organisations consider such research immoral and illegitimate, arguing it constitutes a form of 'speciesism' – prejudice comparable to racism or sexism. This perspective was popularised by Peter Singer in his 1975 book Animal Liberation, which proposed that despite differences between humans and non-humans, both share the capacity to suffer and should therefore receive equal moral consideration in situations where suffering might occur.
Technological advances:
Modern technology has reduced the necessity for some animal studies. Sophisticated scanning techniques enable researchers to observe processes within living human brains under controlled conditions.
Additionally, artificial neural networks – computational models inspired by animal nervous systems (particularly the brain) capable of basic learning, typically presented as interconnected nodes or neurones that compute values from inputs – have been developed. These can be lesioned to examine effects on system functioning.
A separate BPS code of ethics governs psychological research using non-humans, recognising the unique ethical considerations involved in animal research.
Ethics in researching aggression with humans
Research involving human participants presents its own ethical challenges, particularly when investigating aggression.
Issues with scanning techniques:
Scanning techniques carry costs for participants. PET scans require injection of radioactive dye into the bloodstream, and most scans necessitate participants remaining still in an enclosed space for extended periods. This poses protection concerns if a participant is subjected to repeated PET scans.
In Raine's research, for instance, PET scans were used. However, for the control group, scans were conducted for other medical purposes rather than solely for research, and the criminals wished to gather evidence supporting their case that they were not guilty by reason of insanity. Nevertheless, this raises questions about consent and whether the murderers would have participated under duress.
The principle of leaving participants unchanged:
Ethical Principle: Unchanged Participants
One tenet of ethical research states that participants should leave a study in the same state in which they started. It could be argued that undergoing a brain scan might alter this condition.
If a scan identifies brain structural differences associated with impulsive aggression, the person may develop different self-perceptions. For instance, the individual may feel differently about themselves after learning about structural differences in their brain.
Reductionism
Reductionism is the belief that complex phenomena can be explained through simple mechanisms.
Arguments supporting reductionism:
To fulfil scientific requirements, reductionism is necessary because it reduces behaviour to a simple, testable set of variables. However, this may compromise validity as the broader picture is ignored in favour of simplistic and mechanistic explanations.
Scanners can identify which brain regions are active during action performance, but they cannot reveal what motivates us to perform the action initially.
Limitations of reductionist explanations:
Reductionism and Free Will
Reductionist explanations, such as the nativist genetic perspective, suggest a lack of free will as heredity and chemical imbalances supposedly dictate our behaviour. Broader biological theories propose that behaviour such as aggression can be reduced to chemical action in specific brain areas.
Raine discovered that impulsive murderers exhibited differences in activity across various brain regions. The murderers, rather than the researchers, wanted to argue this meant they were somehow less responsible for their actions; indeed, they were attempting to avoid ultimate punishment for their crime by arguing they were only guilty by reason of insanity and tried to prove this by demonstrating their brains operated differently from other people.
The case for holistic explanations:
Such explanations neglect factors at other levels that interact to produce behaviour. Regarding aggression, examining genetic inheritance can only provide part of the picture; it plays a role but cannot explain very few cases of aggression independently.
Holistic Explanation of Aggression
Consider a comprehensive explanation that combines multiple factors:
- Genetic inheritance: Biological predisposition toward aggression
- Family environment: Upbringing where aggression was regularly modelled
- Cultural factors: Social approval of violence in certain contexts
Adding genetic inheritance to an upbringing where aggression was regularly modelled in the family and cultural factors such as approval of violence creates a much more valid explanation than any single factor alone.
Socially sensitive research
Research into aggression is socially sensitive, meaning the findings have social consequences for individuals or groups beyond the study setting itself.
Why aggression research attracts attention:
Socially sensitive research tends to gain media attention because it carries implications for society. Neurological explanations for various behaviour types exemplify such research, including studies linking genetics to homosexuality, intelligence and aggression.
Example: Raine's Research
Adrian Raine's studies represent classic examples discussed earlier in this topic. Raine's research is highly socially sensitive as it challenged the prevailing view that crime resulted from social and environmental factors imposed on individuals, such as poverty during childhood, rather than individual biological differences.
Raine's (1997) research found that brain scans of people convicted of impulsive murder showed differences in areas associated with impulse control. This suggests a physical marker could be identified for this type of crime, potentially enabling future population screening to identify potential criminals.
Historical misuse and contemporary concerns:
Historical Misuse of Biological Research
This research generated controversy because historically, research linking biology to behaviour has been used to justify extremist views and social policies, such as eugenics, where individuals belonging to certain social groups were subjected to compulsory sterilisation (or worse) in attempts to control the gene pool by removing undesirable genes.
One potential outcome of a neuro-criminological stance might be medicalisation of criminal behaviour. If brain scans reveal structural differences associated with aggressive behaviour, perhaps it constitutes a form of disorder or illness. This raises questions about:
- Personal responsibility: Is criminal behaviour beyond individual control?
- Appropriate responses: How should society respond to individuals with biological markers for crime?
- Pre-emptive action: Should action be taken before any crime is committed?
This could be considered an ethical 'slippery slope' that could lead to pre-emptive action being taken to control behaviour of people identified as having biological markers for crime before any crime is committed.
Use of psychological knowledge in society
Psychological knowledge can improve people's lives either by providing treatments or understanding for problem behaviour.
Benefits: Drug addiction treatment:
Positive Application: Addiction Treatment
Drug addiction is one area that has benefited from psychological knowledge. Understanding the physiological changes underlying drug addiction has furthered treatments to the extent that some researchers (Van den Oever et al., 2008) are beginning to develop pharmacological treatments that may be used in future to help avoid relapse.
Benefits: Understanding aggression:
Insight into the contributory role of genes, hormones and brain structures on aggressive behaviour can also benefit society, as understanding the causes of such behaviour means it is possible, in some cases, to avoid it.
Research demonstrates how aggression can result from interaction between genes, hormonal factors and brain structures. This provides an explanation for why some people may be more aggressive than others and potentially allows for risk predictions to be made. This might, in future, allow for those identified as at risk to experience a modified environment that reduces the risk of aggressive behaviour patterns developing, therefore benefiting both the individual and society.
Risks: Social control and labelling:
Social control can result from knowledge about biological factors in behaviour, such as aggression and addiction, because knowing what causes problematic behaviours can mean people may strive to predict which people will develop certain traits.
If research into brain dysfunction, such as Adrian Raine's studies, uncovers biological determinants of aggressive behaviour, researchers may attempt to use this to scan people early in life to identify who is at risk. With this knowledge, there is a possibility that people could be labelled as potentially violent, leading to unfair treatment. If we know who will become violent, we may attempt to control them to prevent the behaviour developing, so they may be subjected to potentially unnecessary monitoring or therapy.
Historical examples of control:
Historical Examples of Control
Unethical treatments, such as prefrontal lobotomies, have been used to control antisocial behaviour, based on weak evidence about the prefrontal cortex's role in controlling behaviour. Despite limited evidence available, during the 1940s and 1950s in the USA, 20,000 such operations took place, often with poor outcomes for patients.
Another way biological knowledge has been used to control people is through chemical castration of males, which involves administering antiandrogenic drugs (male hormone blockers). These reduce the sex drive and some US courts have sentenced male sex offenders to undergo this therapy.
Some would argue this is excessive punishment that unfairly affects the minds and bodies of those to whom it is applied, but others state it allows men convicted of sexual crime to avoid prison. A study into the effects of one such drug found that when taken for a year, it successfully reduced sexually deviant behaviour in males, with no lasting side effects from taking the drug (Gagne, 1981).
Positive applications:
However, as there is no research suggesting any of these biological factors are definitive causes of aggression, this form of control and monitoring may be unfairly administered.
Positive Application: Predicting Aggression in Dogs
In 2014, researchers at the University of Lincoln reported they had been attempting to develop a genetic test to predict aggressive behaviour in dogs. The research aimed to help predict which dogs may be a risk to help owners manage their animals' behaviour better and prevent accidents.
This would be a positive application of this knowledge, so the argument might be that issuing forms of 'social control' in relation to predicting aggression do not have to be considered negative.
Psychology as a science
The biological approach is arguably the most scientific in psychology. It possesses subject matter comprising physical aspects of behaviour that can be objectively measured.
Scientific credibility:
Changes in the chemical composition of synapses can be measured using sensitive mass spectrometry, a technique that can identify the amount and types of chemicals present in a brain tissue sample based on their mass and charge. Such scientific techniques can serve to increase the credibility and status of psychology, making it more aligned with the natural sciences of biology, chemistry and physics.
Limitations of objectivity:
However, not all measures in biological psychology are completely objective, as seen in this topic. The correlational method is a common technique that lacks some scientific rigour in that clear cause and effect conclusions cannot be drawn.
Ethically, sometimes this is all that can be established as full experimental research could require manipulation of an aspect of human physiology. For example, controlling hormone levels associated with aggressive behaviour in groups of babies to establish whether such hormones affect their development.
Reductionism concerns:
The use of scientific techniques that identify and measure physical structures has led to much deeper understanding of the central nervous system and has established facts about behaviour foundations, such as how synaptic transmission works and the role of the action potential.
However, this leaves psychology open to reductionism charges as it seeks and identifies simple biological mechanisms that underlie complex human behaviours, such as aggression.
Historical development of psychological understanding
Physiognomy (judging someone's nature or character by their appearance) has been evident throughout history and only with recent scientific advances in brain scanning has the focus of biological explanations shifted to brain structure and function.
19th and early 20th century theories:
Lombroso's Theory
In the late 19th and early 20th centuries, explanations for criminal behaviour (including aggression) drew upon Darwin's theories and included work by Lombroso (1835–1909).
Lombroso proposed there was a physical 'type' of person linked to crime, and such types represented a more primitive version of humanity, essentially uncivilised in nature, thereby linking a form of behaviour to a physical difference between people.
Although Lombroso's specific ideas have been discredited, the notion that genetic makeup plays a part in criminal behaviour has not. Recent studies, such as Barnes, Beaver and Boutwell (2011), do demonstrate that for lifelong persistent criminal behaviour there appears to be a strong genetic influence, but this is not manifested in physiognomy.
Galton and phrenology:
Sir Francis Galton, working around the same time as Lombroso, took a more scientific stance and photographed criminals to produce a composite picture of a 'criminal', thus identifying physical characteristics associated with crime.
Phrenologists related the role of brain structure to behaviour and personality by attempting to map behavioural characteristics to bumps on the head, supposedly caused by brain areas that differed in size. Such ideas now are regarded as pseudoscientific.
Modern developments:
Early treatments for psychological conditions included trepanning, which is simply boring a hole in the skull with the intention of letting 'evil spirits' out. However, nowadays, trepanning is only done in emergencies to relieve swelling on the brain, and is based on reliable information from brain scans, such as CAT or MRI, that show clearly what is occurring within the skull.
Evolution of Research Focus
Research focus has changed over time in a clear progression:
- Lombroso's era: Very broad, obvious physiological differences
- Phrenology period: Less obvious brain structural differences that led to study of formation of bumps on the skull
- Modern era: Brain-scanning techniques, such as those used by Raine, that can identify subtle structural and functional differences
Nature versus nurture debate
Theories within the biological approach tend to have their roots in the nature side of the debate, as they often focus on the role genetics plays in programming how biological structures develop in the brain and/or in influencing hormone release.
Evidence for genetic influences:
This can be seen in genetic studies suggesting a role for heredity in aggression, such as that of Brendgen et al. (2005) who found high concordance for physical aggression in MZ twins compared to DZ twins.
Evolutionary explanations:
The nature side of the debate encompasses evolutionary explanation of human behaviour by proposing that aspects of human behaviour are biologically determined. This is because genes that programme for such behaviour convey an adaptive advantage for individuals who possess them, which leads to those genes surviving and being passed on through generations.
Evolutionary Explanation of Male Aggression
This includes behaviour such as male aggression, because a clear adaptive advantage can be proposed for it. However, because the genome changes very slowly compared to the environment, these genes are still present, as they do not convey any disadvantage for males who have them.
However, such explanations can be criticised because they cannot be subjected to direct scientific testing as the conditions in which the genome developed no longer exist.
Limitations of pure genetic determinism:
An extreme version of this view of genetic determinism ignores the role of nurture provided by the environment as the person grows and develops. As seen in the section on socially sensitive research, this can be detrimental both to individuals and to society.
Furthermore, no sensible psychologist would take such an extreme stance. The brain continues to develop throughout life, especially during childhood, and its structure is affected by experience, showing how nature and nurture are interactive.
Evidence for environmental influences:
Research on rats, in which they are allocated to an enriched or impoverished environment for an extended period and then measures taken of their brain density, has repeatedly shown that those given the enriched environment have greater cortical density than those in the poor environment, thus showing that nurture affects our biology.
Post-mortem studies comparing the brain density of college-educated individuals with that of less well-educated individuals found more dendrites on the nerve cells of college-educated individuals, suggesting a similar environmental effect can be found in humans (Jacobs et al., 1993).
Example: London Taxi Drivers
Maguire et al. (2006) established differences in the hippocampal areas (involved in consolidation of spatial memory) in licensed London taxi drivers compared to matched controls, showing how lifestyle contributes to changes in brain structure.
This demonstrates that even in adults, the brain remains plastic and responsive to environmental demands, supporting an interactionist perspective.
The interactionist approach:
An interactionist approach to this debate is therefore supported by the evidence rather than a nature or nurture view.
Social control
Social control can result from knowledge about the role of biological factors in behaviour, such as aggression and addiction, because knowing what causes problematic behaviours can mean that people may strive to predict which people will go on to develop certain traits.
Risk prediction and labelling:
If research into brain dysfunction, such as the studies of Adrian Raine, uncover biological determinants of aggressive behaviour, researchers may try to use this to scan people early in life to find out who is at risk. With this knowledge, there is a possibility that people could be labelled as potentially violent, leading to unfair treatment.
If we know who will become violent, we may try to control them to prevent the behaviour developing, so they may be subjected to potentially unnecessary monitoring or therapy.
Historical examples of unethical control:
Unethical treatments, such as prefrontal lobotomies, have been used to control antisocial behaviour, based on weak evidence about the prefrontal cortex's role in controlling behaviour. Despite the limited evidence available, during the 1940s and 1950s in the USA, 20,000 such operations took place, often with poor outcomes for the patients.
Another way in which biological knowledge has been used to control people is through the chemical castration of males, which involves giving antiandrogenic drugs (male hormone blockers). These reduce the sex drive and some US courts have sentenced male sex offenders to undergo this therapy. Some would argue that this is an excessive punishment that unfairly affects the minds and bodies of those to whom it is applied, but others state that it allows men convicted of sexual crime to avoid prison.
A study into the effects of one such drug found that, when taken for a year, it successfully reduced sexually deviant behaviour in males, and that there were no lasting side effects from taking the drug (Gagne, 1981).
Limitations of biological determinism:
However, as there is no research suggesting that any of these biological factors are definitive causes of aggression, this form of control and monitoring may be unfairly administered.
Positive applications:
In 2014, researchers at the University of Lincoln reported that they had been trying to develop a genetic test to predict aggressive behaviour in dogs. The research aimed to help predict which dogs may be a risk, to help owners manage their animals' behaviour better and to prevent accidents. This would be a positive application of this knowledge, so the argument might be that issuing forms of 'social control' in relation to predicting aggression do not have to be considered a negative.
Practical issues in research design and implementation
Brain scans are incredibly complex methods of data collection that are becoming more popular in biological research as the methods are developed further.
Limitations of brain scanning:
Flaws in Brain Scanning Techniques
Many argue though that whilst brain-scanning techniques are hailed as objective measures of brain structure and function, they are heavily flawed and may not tell us what they claim to.
When scans take images of the brain, the scanner picks up lots of information that it then has to collate and interpret to create the image that can then be used by the researchers. Often brain activity is widespread during different activities; for example, reading a book may require use of a variety of different brain areas rather than just one 'reading' brain centre.
This means that when we look at very complex behaviours, the images are unlikely to show only one brain area as being active, and if it did, this would probably be very unreliable.
Issues with Raine's research:
Consider Raine et al.'s (1997) study into impulsive murderers in which many different brain regions showed 'abnormal' levels of activity. However, when comparing this study to other similar studies, the role of the prefrontal cortex is highlighted as being important in this kind of impulsive aggression, but we have no way of knowing whether this is just a small part of a much larger brain activity pattern associated with this type of behaviour.
Simply because the findings have been supported by other brain-scanning studies does not automatically make the findings more reliable.
Methodological concerns:
Reliability Concerns
There is a possibility that some of these supposed patterns of activity associated with behaviours such as aggression occur purely by chance.
When the scanners are sifting through a vast amount of information about the structure and function of brain areas, using the same scanners with the same interpretation mechanisms will undoubtedly yield similar results, but if the scanning method itself is flawed, the evidence gathered has no reliability.
Remember!
Key Points to Remember:
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Animal research offers practical advantages (simpler nervous systems, controlled environments, invasive procedures possible) but raises ethical concerns about animal welfare and rights.
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Reductionism refers to explaining complex behaviours through simple biological mechanisms; whilst this increases scientific testability, it may sacrifice validity by ignoring broader contextual factors.
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Socially sensitive research in biological psychology can have implications beyond the study itself, including historical misuse (eugenics) and contemporary concerns about labelling and social control.
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The nature versus nurture debate is best understood through an interactionist approach – evidence shows that genetic predispositions and environmental factors work together to shape behaviour and brain structure.
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Brain scanning techniques, whilst increasingly sophisticated, have significant limitations including reliability concerns and the difficulty of interpreting complex, widespread patterns of brain activity.