biological factors Flashcards
what could the root cause be of this
substance misuse, genetics or poor diet
how is serotonin linked to aggression
Acts as an inhibiting neurotransmitter
reduced serotonin stops this from working as effectively meaning impulsive behaviors are not being stopped
how is dopamine linked to aggression
an excitatory neurotransmitter, associated with reward pathways and communication.
when are aggressive we release dopamine – which encourages us to repeat the action which explains why people find pleasure in being aggressive
what is the role of the amygdala
processes emotions and links them to memories and behaviors
governs emotional responses of events
how is the amygdala linked to aggression
doesn’t directly cause aggression, but is involved in processing or inhibiting emotional responses, such as anger making it important for aggression
what is a hormones that can be linked to aggression (2)
testosterone
cortisol
should levels of testosterone be raised for it to be linked
yes
how do we know this
Males typically secrete more testosterone than females and males also tend to display more aggression than females (90% of violent crimes and 95% of domestic violence acts are committed by men according to U.S. Department of Justice statistics)
what does the basal model of testosterone say
an increase in testosterone triggers arousal and the male becomes more dominant- this is used for threat responses
higher levels mean that men can survive and reproduce as they can protect (relationships link?)
Dominant behaviour is expressed is through aggressive or violent actions
what is the role of cortisol
regulates bodys stress response
how does cortisol link to aggression
mediates the effect of testosterone on aggression.
The more stressed we are, over a longer period uses up our cortisol – so testosterone is left unchecked
Low levels of cortisol mean that we are unable to mediate the aggressive effects of testosterone effectively, leading to more aggressive behavior
what evolutionary explanation does genetic transmission offer
(think also about studies- not a specific one tho)
aggression as an adaptive behavior, where more aggressive humans are more likely to survive and reproduce (can link to partner preference in relationships)
Genetic studies, like selective breeding have been able to select aggressive traits in animals and breed generations which have more aggression than the previous generations- such as in dog
what is an example of a genetic mutation
(may not be fully relevant idk)
47 XYY Karyotype
how to remember: most individuals have 46 chromosomes so these males have an extra Y chromosome meaning they have XYY instead of XY
who studied this
Sandberg (1971)
what was found
In the 1970s there were studies which found a significant increase in XYY people in secure hospitals because of violence and aggression
whats a drawback of this
but outdated
modern psychology has tended to exclude this as a suggestion, as we now have a better understanding of these ideas and have studied non-aggressive XYY people.
what gene is associated with aggression
MAOA
what does this gene do
gene controls an enzyme (monoamine oxidase A) that breaks down neurotransmitters such as dopamine, noradrenaline, and serotonin
what does a faulty MAOA lead to
higher than usual levels of serotonin
how does it lead to these higher levels of serotonin
the variant of the gene is overactive in neutralizing serotonin, so it cant be resynthesized back into the presynaptic transmission sight
messes with serotonin regulation causing us to be aggressive
higher serotonin can contribute to goal-directed, dominance-related aggression in certain contexts
what are the two types of MAOA
MAOA-L
MAOA-H
what happens with MAOA-L (very good evidence)
produces low levels of the enzyme (monoamine oxidase A- breaks down neurotransmitterswh)
serotonin becomes too active generating a lower sensitivity to the effects of inhibition as there is so much serotonin it just gets ignored
carriers of this are very aggressive
what is some evidence to support this
Reif et al. (2007) - 45% of aggressive participants had a faulty MAOA gene (low-activity)
