Agression Flashcards
What does neural influence of aggression refer to?
The effect of neurotransmitters and the nervous said that some people may be somehow more pre disposed to aggression through their biological characteristics.
What is the limbic system?
An area of the brain that helps to co-ordinate behaviour, and especially emotion and motivation. The two key emotions involved in the limbic system are aggression and fear. The limbic system is made up of various parts of the brain, but we focus on amygdala and hippocampus.
What is the Amygdala?
This is the part of the brain responsible for anger. If you artificially stimulate it in an animal they will respond with aimless aggression. If you remove it they will no longer experience rage in response to the same stimuli. The amygdala is the brains quick response to stimuli and is a very primitive part of the brain.
What is the hippocampus?
This is the part of the brain responsible for memory. This helps us to respond to stimuli which we remember should be linked to aggression. Damage to the hippocampus can affect our normal responses to aggression.
What is the role of serotonin in aggression?
Serotonin is a an inhibitory neurotransmitter which helps us to calm down. It inhibits the behaviour of the amygdala which would otherwise make us act aggressively.
Little serotonin -> unable to control rage due to the amygdala being easily activated.
Hormones- how can testosterone affect aggression?
Thought to increase aggressive and dominant behaviour.
It is the male sex hormone and is said to explain the increased male aggression in males once they have reached adolescents.
What evidence supports the role of the amygdala?
Pardini et al (2014) found reduced amygdala volume can predict the development of severe and persistent aggression. 56 participants took part in a longitudinal study. He found that participants with lower amygdala volumes exhibited higher levels of aggression.
What evidence supports the role of the hippocampus?
Raine et al (2004) studies violent offenders. Two groups of violent criminals some who faced convictions and some who had evaded the law. The latter was considered to be ‘cold calculated’ criminals but the former had acted more impulsively. MRI’s revealed asymmetries in the hippocampus of the former group. Different sizes in each hemisphere. It is thought that this might impair the ability of the hippocampus and amygdala working together , so emotional information is not processed correctly leading to an inappropriate response.
What evidence is there against the role of serotonin?
Duke et al (2009) did a meta analysis of 175 studies with 6,500 participants and found inverse relationship between serotonin levels and aggression. He found that the magnitude of relationships varied with methods used to assess serotonin functioning with self reported vs. Other reported aggression. Only other reported aggression positively correlated with aggression which suggests that the relationship is more complex.
Outline the Genetic factors of aggression.
Your likelihood of having a characteristic, based on the presence of that characteristic in your gene pool. E.g. 7 people in a family, each member shares a certain number of genes with each member. The more similar the genes, the higher their likelihood of sharing characteristics such as anger or aggression.
Twin studies can be used to generic factors of aggression. What are the studies that support this?
MZ-share 100% DNA
DZ-share 50% DNA
McGUFFIN AND GOTTESMAN (1985)- Found MZ twin concordance rates for aggression to be 0.87 compared to 0.72 in DZ twins. Not 100% of the MZ twins though and so there must be other factors involved.
COCCARO (1997)- Compared the aggressive tendencies I’d adult twins and concluded that 50% of the violent behaviour was due to genetics..again not 100% and so we can not assume that it is 100% genetics that cause aggression.
What are the problems with Twin Studies?
MZ twins should share an environment to the same extent of DZ twins, but there is not necessarily true. Identical twins are much more likely to be treated identically compared to DZ twins who are more likely to have their own identity.
What is the significance to adoption studies in aggression and what studies support this?
In order to ensure that we may avoid any environmental factors in child rearing we can use adoption studies.
HUTCHINGS AND MEDNICK- Conducted a large adoption study in Denmark, concerning over 14,000 adoptions. They compared the biological parents of adopted boys with criminal convictions with those who did not. They found a significant link.
MILES AND CAREY(1997)- Meta analysis of 24 twin and adoption studies. They found a strong genetic influence accounting for 50% if the violence in aggression. Aggression in youth could be explained through a mixture of genetic and family factors, whereas adult aggression was more closely related to genetic factors instead of family environment.
Strengths of genetic factors in aggression?
RESEARCH SUPPORT- research is not artificial as it was done in a real life situation meaning that it has high ecological validity
COMBO OF TWIN AND ADOPTION STUDIES-Support the idea that aggression is related to genetics(McGUFFIN and GOTTESMAN)
Weaknesses of genetic influences
DIFFICULTY MEASURING AGGRESSION- relies on self reported aggression or observed techniques. -criminal conviction (may be a one off)
TO SIMPLISTIC
ROLE OF OTHER FACTORS.
