Aggression 16 marker essay plans
Neural (inc NT) explanations for aggression (2021)
AO1: Aggression is located in the limbic system of the brain which coordinates behaviour
that satisfies motivational and emotional urges like anger and fear. The hippocampus allows
animals to compare a previous threat to a current one. Impairment in the hippocampus
leads the nervous system to not react appropriately and may cause the amygdala to
respond in aggressive way. The amygdala evaluates sensory information and prompts an
appropriate response. Stimulation of this area in animals causes an aggressive reaction e.g.
pouncing. Removing the amygdala from animals will then cause them not to react to things
that would usually cause them rage. Normal levels of serotonin in neuronal firing in the
brain cause a calming and inhibitory effect but low levels of serotonin cause less inhibition
of the amygdala making aggression more likely. Research shows when drugs are taken to
reduce serotonin levels aggression is more common.
AO3: Pardini et al did a longitudinal study on 56 males with a background of aggression and
used MRI scans to measure the volume of amygdala in their brains and found a relationship
between amygdala and aggression. Low volumes of amygdala means aggression is more
likely as there is less amygdala to moderate aggression levels. Raine et al researched how
the hippocampus was different sizes in the right and left hemisphere of convicted criminals
in comparison to non-convicted criminals. This may cause an impair in communication
between the hippocampi and the amygdala leading to inappropriate emotional responses.
Rosado et al measured the units of serotonin in dogs that were aggressive to humans and
compared them to dogs who weren’t aggressive to humans to find lower units of serotonin
in the aggressive dogs. Yet research into humans sometimes showed a difference in
serotonin levels between aggressive and non-aggressive humans and sometimes did not. In
fact some research showed when men increased their serotonin levels aggression
decreased. Thus, there are problems of extrapolation in Rosado’s study. In general, the
biological approach to aggression is reductionist as it ignores the SLT explanation, the
frustration-aggression model, and the deindividuation model.
Hormonal explanations for aggression (2021)
AO1: Testosterone is a hormone that produces male characteristics including aggression.
Animals with reduced levels of testosterone are likely to be less aggressive compared to
when animals have higher levels of testosterone. As men have higher levels of testosterone,
they are more physically aggressive.
AO3: Dabs et al researched how criminals who had higher testosterone levels committed
more violent crimes whereas criminals with low levels of testosterone committed non-
violent crimes. This provides a link between aggression and testosterone levels. The
problem with this study is that hormonal fluctuations occur throughout the day and the
change in testosterone levels could be due to aggressive activity and not the reason for
aggression. In general, the biological approach to aggression is reductionist as it ignores the
SLT explanation, the frustration-aggression model, and the deindividuation model.
, Genetic explanations for aggression (2021) (2022)
AO1: MAOA is a gene that controls the production of the enzyme MAO-A which regulates
serotonin. Some people have low levels of MAO-A enzyme leading to the low activity
variant of the MAOA gene – the MAOA-L gene nicknamed the warrior gene. 2/3rds of
countries with a history of war have the warrior gene e.g. 56% of New Zealand Mauri men
in comparison to 34% of New Zealand Caucasian men. Research also shows a link between
MAOA-L and aggression. Low activity of the MAO-A enzyme in combination with childhood
abuse leads to a high chance of aggressive behaviour in adulthood. Brunner’s syndrome is a
rare genetic mutation of the MAOA gene which cause hypersexuality and aggression, but it
is rare. The warrior gene is much more common and is in 40% of the population yet it is
clear it does not always lead to aggressive behaviour. Twin studies show that genetics play a
role in aggression as concordance rates between monozygotic twins show that genetics play
a factor. Coccaro et al’s sample of MZ and DZ male twins shows a concordance rate of
displays of physical aggression of 50% in MZ twins and 19% in DZ twins. Adoption studies
also show the role of genetics as if adopted children are like their biological parents then
genetics play a role but if they are like their adopted parents, it is the influence of the
environment. Hutchings and Mednick had a sample of 1400 adopted children in Denmark
and many of the criminally convicted adopted children had biological fathers who were also
criminally convicted.
AO3: Brunner et al researched a Dutch family with a history of violence such as rape and
assault and found they all had abnormally low levels of MAO-A enzyme and all had the
MAOA-L variant of the gene. However, Vassos et al did a meta-analysis on research and
found there is not just one gene that links to aggression and even a polygenetic explanation
cannot explain something as multifaceted as aggression. Hundreds and thousands of genes
play a role in aggression, and it cannot be reduced to just one. The genetic explanation of
aggression is also reductionist as it simplifies a complex concept. However, there also legal
implications of MAOA as in 2009 a criminal successfully reduced his sentence by arguing
that he had the MAOA-L gene and a history of child abuse. Caspi et al suggested a GxE
(genetic and environmental interaction) model as a diathesis stress model is more likely to
explain aggression. He had a sample of 500 boys who all had the MAOA-L variant of the
gene and displayed anti-social behaviour only if they also had experienced childhood
neglect. This shows that environment plays just as a much of a role in determining
aggressive behaviour and cannot be explained by genetics alone. In general, the biological
approach to aggression is reductionist as it ignores the SLT (Bandura and Kray twins)
explanation, the frustration-aggression model, and the deindividuation model. The genetic
explanation of aggression also ignores social and environmental factors.
Describe and evaluate evolutionary explanations for human aggression (2017)
AO1: The evolutionary explanation for aggression is that aggression has evolved due to its
adaptive qualities in solving problems for humans in the past. Examples of adaptive qualities
include gaining resources, gaining status, eliminating competition for mates, and deterring
infidelity. Aggression has helped survival and reproduction for previous humans, so it is now
inherited by offspring. Sexual competition is also higher for men as competition for mates in
the past was more extreme for them as the biggest problem towards reproduction was
looking for fertile mates making competing important. Aggression over competing often led
Neural (inc NT) explanations for aggression (2021)
AO1: Aggression is located in the limbic system of the brain which coordinates behaviour
that satisfies motivational and emotional urges like anger and fear. The hippocampus allows
animals to compare a previous threat to a current one. Impairment in the hippocampus
leads the nervous system to not react appropriately and may cause the amygdala to
respond in aggressive way. The amygdala evaluates sensory information and prompts an
appropriate response. Stimulation of this area in animals causes an aggressive reaction e.g.
pouncing. Removing the amygdala from animals will then cause them not to react to things
that would usually cause them rage. Normal levels of serotonin in neuronal firing in the
brain cause a calming and inhibitory effect but low levels of serotonin cause less inhibition
of the amygdala making aggression more likely. Research shows when drugs are taken to
reduce serotonin levels aggression is more common.
AO3: Pardini et al did a longitudinal study on 56 males with a background of aggression and
used MRI scans to measure the volume of amygdala in their brains and found a relationship
between amygdala and aggression. Low volumes of amygdala means aggression is more
likely as there is less amygdala to moderate aggression levels. Raine et al researched how
the hippocampus was different sizes in the right and left hemisphere of convicted criminals
in comparison to non-convicted criminals. This may cause an impair in communication
between the hippocampi and the amygdala leading to inappropriate emotional responses.
Rosado et al measured the units of serotonin in dogs that were aggressive to humans and
compared them to dogs who weren’t aggressive to humans to find lower units of serotonin
in the aggressive dogs. Yet research into humans sometimes showed a difference in
serotonin levels between aggressive and non-aggressive humans and sometimes did not. In
fact some research showed when men increased their serotonin levels aggression
decreased. Thus, there are problems of extrapolation in Rosado’s study. In general, the
biological approach to aggression is reductionist as it ignores the SLT explanation, the
frustration-aggression model, and the deindividuation model.
Hormonal explanations for aggression (2021)
AO1: Testosterone is a hormone that produces male characteristics including aggression.
Animals with reduced levels of testosterone are likely to be less aggressive compared to
when animals have higher levels of testosterone. As men have higher levels of testosterone,
they are more physically aggressive.
AO3: Dabs et al researched how criminals who had higher testosterone levels committed
more violent crimes whereas criminals with low levels of testosterone committed non-
violent crimes. This provides a link between aggression and testosterone levels. The
problem with this study is that hormonal fluctuations occur throughout the day and the
change in testosterone levels could be due to aggressive activity and not the reason for
aggression. In general, the biological approach to aggression is reductionist as it ignores the
SLT explanation, the frustration-aggression model, and the deindividuation model.
, Genetic explanations for aggression (2021) (2022)
AO1: MAOA is a gene that controls the production of the enzyme MAO-A which regulates
serotonin. Some people have low levels of MAO-A enzyme leading to the low activity
variant of the MAOA gene – the MAOA-L gene nicknamed the warrior gene. 2/3rds of
countries with a history of war have the warrior gene e.g. 56% of New Zealand Mauri men
in comparison to 34% of New Zealand Caucasian men. Research also shows a link between
MAOA-L and aggression. Low activity of the MAO-A enzyme in combination with childhood
abuse leads to a high chance of aggressive behaviour in adulthood. Brunner’s syndrome is a
rare genetic mutation of the MAOA gene which cause hypersexuality and aggression, but it
is rare. The warrior gene is much more common and is in 40% of the population yet it is
clear it does not always lead to aggressive behaviour. Twin studies show that genetics play a
role in aggression as concordance rates between monozygotic twins show that genetics play
a factor. Coccaro et al’s sample of MZ and DZ male twins shows a concordance rate of
displays of physical aggression of 50% in MZ twins and 19% in DZ twins. Adoption studies
also show the role of genetics as if adopted children are like their biological parents then
genetics play a role but if they are like their adopted parents, it is the influence of the
environment. Hutchings and Mednick had a sample of 1400 adopted children in Denmark
and many of the criminally convicted adopted children had biological fathers who were also
criminally convicted.
AO3: Brunner et al researched a Dutch family with a history of violence such as rape and
assault and found they all had abnormally low levels of MAO-A enzyme and all had the
MAOA-L variant of the gene. However, Vassos et al did a meta-analysis on research and
found there is not just one gene that links to aggression and even a polygenetic explanation
cannot explain something as multifaceted as aggression. Hundreds and thousands of genes
play a role in aggression, and it cannot be reduced to just one. The genetic explanation of
aggression is also reductionist as it simplifies a complex concept. However, there also legal
implications of MAOA as in 2009 a criminal successfully reduced his sentence by arguing
that he had the MAOA-L gene and a history of child abuse. Caspi et al suggested a GxE
(genetic and environmental interaction) model as a diathesis stress model is more likely to
explain aggression. He had a sample of 500 boys who all had the MAOA-L variant of the
gene and displayed anti-social behaviour only if they also had experienced childhood
neglect. This shows that environment plays just as a much of a role in determining
aggressive behaviour and cannot be explained by genetics alone. In general, the biological
approach to aggression is reductionist as it ignores the SLT (Bandura and Kray twins)
explanation, the frustration-aggression model, and the deindividuation model. The genetic
explanation of aggression also ignores social and environmental factors.
Describe and evaluate evolutionary explanations for human aggression (2017)
AO1: The evolutionary explanation for aggression is that aggression has evolved due to its
adaptive qualities in solving problems for humans in the past. Examples of adaptive qualities
include gaining resources, gaining status, eliminating competition for mates, and deterring
infidelity. Aggression has helped survival and reproduction for previous humans, so it is now
inherited by offspring. Sexual competition is also higher for men as competition for mates in
the past was more extreme for them as the biggest problem towards reproduction was
looking for fertile mates making competing important. Aggression over competing often led
