biological explanation

• Neural and Hormonal Mechanisms pt 1 : There is strong empirical support for the role of serotonin in regulating aggression. Raleigh et al. (1991) found that monkeys with diets that increased serotonin levels were less aggressive, providing direct evidence for a causal link between serotonin and aggression. Similarly, human studies suggesting that serotonin has an inhibitory effect on aggression. As a result the scientific nature of these studies ensure high validity for the direct impact serotonin has on aggression
• Neural and Hormonal Mechanisms pt 2: However, this biological explanation is often criticized for being biologically deterministic, implying that individuals with low serotonin levels are inevitably aggressive. This perspective oversimplifies human behavior by ignoring environmental and psychological influences, such as upbringing, peer influence, or situational factors, which can modulate aggressive impulses.
• Neural and Hormonal Mechanisms pt 3: Moreover, such biological determinism can raise ethical concerns about accountability, particularly in legal cases where aggressive offenders may claim their behavior is driven by uncontrollable biological factors. While serotonin and other neural mechanisms play a crucial role in aggression, a more holistic approach that integrates both biological and environmental factors would provide a more comprehensive explanation and better align with the defence of criminals whose aggression has lead to illegal behaviour.
• Genetic Factors in Aggression pt 1: The genetic basis of aggression is supported by a range of studies, such as Brunner et al. (1993), who investigated a Dutch family with a history of violent behavior and found a mutation in the MAOA gene, which regulates the metabolism of neurotransmitters involved in mood regulation. This suggests that certain individuals may be genetically predisposed to aggression due to deficits in regulating critical brain chemicals like serotonin
• Genetic Factors in Aggression pt 2: However, the genetic explanation faces criticism for being overly reductionist. By focusing primarily on genes, it neglects the significant role of environmental factors, such as childhood trauma or social learning, which also contribute to the development of aggressive behavior. For example, twin studies show only partial concordance rates for aggression, indicating that genetics alone cannot fully explain aggressive behavior.
• Genetic Factors in Aggression pt 3: Additionally, the nature vs. nurture debate remains contentious, as it is often difficult to disentangle genetic influences from environmental factors in human behavior. Overall, while genetic factors may predispose individuals to aggression, they likely interact with environmental triggers, which are equally important in understanding aggressive behavior.
• how does the amygdala influence aggression?

  the amygdala, part of the brains limbic system, plays a key role in processing emotions, particularly fear and anger. It triggers aggressive responses when individuals perceive a threat. Overactivity in the amygdala is linked to increased aggression, as it makes people more sensitive to potential threats, which can escalate into aggressive behaviour. Research on animals (eg removal or stimulation of the amygdala) has shown changes in aggression levels, supporting its role in aggression in humans.
• How do hormones influence aggression?

  High levels of testosterone are linked to increased aggression, particularly in males. Testosterone is thought to increase dominance and competitiveness, which can lead to aggressive behavior.
• how does serotonin regulate aggression

  serotonin is a neurotransmitter that normally inhibits aggression by regulating mood and emotional response. Low levels of serotonin reduce an individuals ability to control impulsive and aggressive behaviour. Raleigh et al found that monkeys with low serotonin levels displayed more aggression. Serotonin's inhibitory effect means that when levels are low, individuals are less able to control their aggressive impulses, making them more prone to aggressive outbursts.
• how does the amygdala influence aggression

  the amygdala is part of the brains limbic system, which processes emotions like fear and anger. When the amygdala is overactive, it heightens emotional responses to perceived threats, leading to aggressive behavior. Studies using brain imaging have shown that individuals with heightened aggression often display increased activity in the amygdala suggesting its critical role in triggering aggressive responses.
• what is the relationship between testosterone

  testosterone is a hormone linked to dominance and competitive behaviours, found in higher levels in males. research has shown that individuals with higher testosterone levels tend to display more aggressive behaviors. For example dabbss et al found that violent criminals had higher levels of testosterone compared to non-violent criminals. testosterone affects brain areas involved in regulating aggression such as the amygdala and hypothalamus contributing to heightened aggression.
• what is the MAOA gene, and how does it relate to aggression 


  the MAOA gene regulates the metabolism of neurotransmitters such as serotonin. individuals with a low-activity variant of this gene produces less of the enzyme, leading to higher levels of neurotransmitters associated with aggressive behaviour. The Brunner et al study on a Dutch family with a history of violent behaviour found that the men had a defective version of the MAOA gene, suggesting a genetic predisposition to aggression.
• How do twin studies support the genetic explanation for aggression

  Twin studies compare aggression levels in monozygotic (MZ) twins who share 100%of their genes, with dizygotic (DZ) twins suggest that genetics play a significant role. For example Coccaro et al found concordance rates for aggressive behaviour were 50% for MZ twins and 19% for DZ twins indicating a genetic contribution to aggression, although environmental factors are also important as concordance is not 100%
• limbic system 


  a group of structures in your brain that regulate your emotions, behavior, motivation and memory.
• MOAO gene 


   an enzyme whose role is to mop up neurotransmitters in the brain after nerve impulses have been transmitted from one neuron to another.
• neural and hormonnal pt 22

  furthermore, serotonin is a complex neurotransmitter that inhibits levels when either too high or too low, and differently in different people. individualism is being ignored with the hard deterministic stance of aggression