Neural and Hormonal explanations Flashcards
Neural Mechanisms
-Things related to the neuron, such as large neural structures or actions of neurotransmitters
Hormonal Mechanisms
-How chemical messengers influence the body
Limbic System
-A set of neural structures located in the center of the brain i.e the hypothalamus and amygdala that process emotional responses such as aggression
Serotonin in the context of aggression
-Serotonin is a neurotransmitter that acts as an inhibitor in the brain, reducing neural activity
-Serotonin in the orbitofrontal cortex controls/dampens aggressive impulses coming from areas of the limbic system, i.e the amygdala; maintaining a stable, calm mood
Evaluation of Serotonin as an an explanation (strength)
-Research supports that increased levels of serotonin reduces aggressive behavior
-Researchers found that when participants were given a drug that increases serotonin levels, their levels of aggression when playing a video game decreased compared to a control group
Testosterone in the context of aggression
-Testosterone is a male sex hormone that is associated with increased levels of aggression in males
-High levels of testosterone reduce activity in the orbifrontal cortex
-This means that the orbifrontal cortex is less likely to be able to regulate aggressive impulses produced by the limbic system
-High testosterone levels also increase the activity of the amygdala, causing there to be more aggressive responses
-High testosterone also decreases serotonin levels, reducing its ability to inhibit/control aggressive responses
Testosterone Evaluation (mice biting study)
Researcher measured aggression in mice by how many times they bit a target
-They found that male mice bit more than females
-However this sex difference stopped when they were castrated
-and then it started up again when they were injected with testosterone
-this supports the theory that high levels of testosterone contribute to aggressive behaviour
Amygdala
-Part of the limbic system
-The amygdala has been identified to be linked to aggressive behaviour
-FMRIs show increased activity at the amygdala during aggressive responses
Hypothalamus
has a role in the expression of emotional responses
it can trigger behavior as part of the fight or flight response
Orbitofrontal cortex
-Involved in decision making
-attempts to control aggressive impulses produced by the limbic system
Evaluation for neural and hormonal explanations of aggression
Researchers carried out a case study on a 14-year-old girl showing extreme aggressive behavior
-MRI scans revealed that she had a tumor that was pressing up against her amygdala
-Once the tumor levels were removed, aggression levels returned to normal, suggesting that the tumor was stimulating the amygdala, causing the aggressive behavior
-This supports the theory that the amygdala is linked to aggressive behavior
However on the case study
As it was a case study on one individual, there may be other factors influencing aggression
Serotonin deficiency hypothesis + MAOA gene
Lower than normal levels of serotonin levels in the orbifrontal cortex results in less self control over aggressive impulses produced by the limbic system
-However, the role of serotonin is complex, as those with the MAOA gene struggle to break down serotonin and therefore have increased levels of it, but are more aggressive.
Evaluation of the neural and hormonal explanation for aggression (biological determinism)
This explanation is biologically deterministic. In extreme cases, people may use this as an excuse for their behaviour. For example in criminal cases in the US, murderers may claim that their behaviour is determined by hormonal imbalances or neural abnormalities.
Evaluation of neural and hormonal explanations of aggression (Scientific credibility)
The use of highly controlled methods, measuring objective biological elements means that research supporting this explanation often have a very high internal validity.
