Aggression Flashcards
What is the limbic system? And how does it give a hormonal explanation for aggression?
- The Limbic System (including the Hypothalamus and Amygdala) tends to act as an alarm system triggering aggressive response to certain types of threats.
- Giving testosterone to new-born female mice made them act like males with increased aggression, when given testosterone as adults. However, control females only given testosterone as adults did not react in this way (Edwards ,1968).
This suggests that testosterone masculines androgen-sensitive neural circuits underlying aggression in the brain.
What 2 research studies provide evidence for the limbic systems role in aggression?
Research in Greece found that removing the amygdala reduced aggressive incidents by between 33% and 100%, although the sample was small – 13 patients.
The Phineas Gage study provides evidence that brain damage may have an effect on personality including aggression.
What research has been done into serotonin what are its effects and what gene is responsible for its production?
- The PET-1 Gene is linked to the production of the hormone serotonin, which inhibits (i.e. stops) aggression. Damage to the gene, in mice, raises aggression. [sometimes referred to as “Knockout Mice] (Deneris, 2003).
- Drugs increasing serotonin production lead to reduced levels of aggression, suggesting that low levels of serotonin are linked to increased aggression (Delville et al., 1997).
What 3 research examples can be used in reference to serotonin?
- Rats selected for reduced aggression levels had higher serotonin and greater levels of serotonin related activity than wild, more aggressive counterparts (Popova et al., 1991).
- Research shows a relationship between low levels of serotonin and violent behaviors, suggesting that a lack of serotonin is linked to aggression (Linnoila & Virkunen, 1992).
- Lidberg et al. (1985) compared serotonin levels of violent criminals with non-violent controls, finding the lowest levels of serotonin among violent criminals.
How does cause and effect prove a limitation to research into serotonin?
Most evidence linking low levels of serotonin and aggression is only correlational and does not indicate causality.
How is testosterone levels linked to aggression?
• Giving the hormone testosterone to new-born female mice made them act like males with increased aggression, when given testosterone as adults.
However, control females only given testosterone as adults did not react in this way, suggesting that testosterone masculinises androgen-sensitive neural circuits underlying aggression in the brain (Edwards ,1968).
What 4 research studies can be used in relation to Testosterone levels?
Testosterone affects certain types of aggression in animals, such as intermale aggression as a defence response to intruders, while predatory aggression is not affected (Bermond et al., 1982).
• Van Goozen (1997) conducted a natural experiment on trans-gender sex-change patients. This is one of the few cases where research was actually carried out on humans.
Findings revealed testosterone levels governed aggression. Males receiving testosterone suppressants became less aggressive. Females receiving testosterone became more aggressive.
• Aggressive Boys, violent criminals, military offenders all had high levels of testosterone (Dabbs, 1996).
Who showed that cognitive and social roles play into aggression?
Individuals with elevated testosterone levels exhibit signs of aggression, but rarely commit aggressive acts, suggesting that social and cognitive factors play a mediating role (Higley et al., 1996).
Who showed that social context and economic situation played into aggression (weakness to testosterone)
Dabbs and Morris (1990) ‘Blocked pathways to success’ study: When a rich boy with high testosterone came home from the army he was less likely to get into trouble, but when a poor boy with high testosterone came home he was more likely to get into trouble.
This suggests testosterone doesn’t simply cause aggression, but it makes aggression more likely as a response to frustration.
How has cortisol research lead to a correlation to aggression?
- The fearlessness Theory: Stress, caused by the hormone cortisol may inhibit aggression through fear. So individuals with lower levels of cortisol are less inhibited, more inclined to take risks and act impulsively (Raine, 2002).
- Low cortisol leads to Sensation seeking behavior, especially in males (Zuckerman, 2010).
- Low levels of Cortisol in delinquent teenagers with conduct disorder (Fairchild, 2008)
How is the correlation in all neural and hormonal explanations for aggression a limitation?
Much of the evidence is only correlational and may not prove causation. It isn’t clear whether hormones promote aggression, or aggressive behaviour stimulates hormone production.
How is their a problem with the applicability of most research into neural and hormonal explanations?
Comparative – much of the work on hormones and neurotransmitters has been done on animals and may not apply to humans so easily.
How is the reductionist approach of neural and hormonal explanations for aggression a weakness?
Reductionist: Sees only biological factors, overlooking social issues such as de-individuation Heredity / Environment: Biological theories tend to overlook the effects of socialisation and other environmental issues, such as environmental stressors.
How is a limitation of neural and hormonal explanations for aggression its deterministic stance?
Deterministic: Assumes humans have no choice and will follow primitive behaviour patterns. Ignores any free will that we have.
How have animal studies shown the genetic basis for aggression?
And twin studies?
And police records?
Animal studies show instinctive patterns of behavior including aggressive behavior. If a whole species has a similar level of aggression then it must have a genetic basis.
• Twin studies have shown that twins have similar levels of aggression.
Using old Danish police records Christiansen (1977) demonstrated that levels of criminality showed a stronger correlation between identical twins – with the same genes – than between dizygotic twins.
What is a weakness of the police records study in terms of genetic basis for aggression?
However criminality is not always the same as aggression.
What research has been done into the genetic basis of serotonin and therefore aggression?
- PET-1 Gene is linked to serotonin production which inhibits aggression. Damage to the gene in so called “knockout mice” raises aggression. Mutations in humans can have the same effect (Deneris, 2003).
- Acts of impulsive aggression, such as domestic violence, have a genetic link to the serotonergic system, suggesting that many genes may be involved in aggression (New et al., 2003).
What is the role of the MAOA gene and what is it called?
MAOa is an enzyme which helps with the re-uptake of neurotransmitters including serotonin. Humans with the MAOa L gene (L is for Low) have a lack of MAOa enzyme. Without this enzyme to recycle it the level of serotonin may become depleted.
What 3 studies can be used in reference to the MAOA gene?
African american, dutch, abuse
When researchers found the MAOa-L gene present in 56% of New Zealand Maori men it was nicknamed “The Warrior Gene”. Poa {2006] criticised this term as unethical - i.e. racist.
It was later found that the gene is present in 58% of African American men and 36% of European men, so it is actually a mainstream genetic variation with adaptive advantages associated with risk taking.
- A Dutch family has long history of aggression, and a genetic inability to process serotonin due to lack of MAOA (Brunner, 1993)
- Caspi et al (2002): Interaction of MAOA problem AND abusive childhood led to aggression. If boys with the MAOa – L gene suffered abuse in childhood , they were 3 times more likely to be aggressive when they reached adulthood.
What 3 studies can be used in reference to the genetic basis of testosterone?
(inheritance, mice, sry gene)
Bogaert et al. (2008) established that variations in male testosterone levels are inherited – and therefore genetic.
- Giving testosterone to newborn female mice made them act like males with increased aggression, when later given testosterone as adults. Females only given testosterone as adults did not react in this way, suggesting that testosterone masculinises aggression systems in the brain at birth, it’s not just an environmental issue (Edwards, 1968).
- Rissman et al. (2006) investigated Sry, a gene leading to the development of testes and high androgen levels in males. Male and female mice with and without the gene were tested. The Sry gene was associated with high levels of aggression, suggesting that genes and hormones interact and that sex chromosome genes also have a role.
What research has been done in relation to gender and aggression?
Rissman et al. (2006) investigated Sry, a gene leading to the development of testes and high androgen levels in males. Male and female mice with and without the gene were tested. The Sry gene was associated with high levels of aggression, suggesting that genes and hormones interact and that sex chromosome genes also have a role.
How are the tests done on the genetic basis of aggression un-applicable?
Comparative – much of the work on genes has been done on animals and may not apply to humans so easily. However, the experiments which have been done on mice relate to chemicals and genes which are very similar.
How is the reductionist approach of the genetic basis for aggression a limitation?
Reductionist: Danger of seeing only biological and overlooking social psychology issues such as de-individuation. Tends to overlook the effects of socialisation and other environmental issues, such as environmental stressors. Genetic factors do not work in isolation but interact with environmental factors as well.
How is the deterministic stance on aggression a limitation?
Deterministic: Assumes that humans have no choice and will follow quite primitive behaviour patterns.
What is Ethology and who proposed it as an explanation for aggression and how did he say it worked?
Ethology is where we learn about human psychology from studying other animals.
- Conrad Lorenz believed that aggression was an innate adaptive response – something which had evolved in humans and animals to help them survive.
- To see off predators: For example a group of hissing geese can drive off a fox, even though the fox would probably win a straight fight. If the geese survive, then the gene which led to that aggressive response will be passed on.
- To get resources: Lorenz also suggested that much aggression was aimed at members of the same species, when competing for territory or sexual partners, but some animals are so fierce they could easily damage each other when fighting for dominance; Eg. Wolves, Stags, Lions.
What does the aggression in ethology lead to and who called it fixed action patterns?
This would be maladaptive – bad for the species. Therefore they fight until one backs down, not to the death, just to establish who is stronger and who is weaker.
This creates a society in which each individual knows their place. They have evolved ways of warning others to back off: Dogs bark and snarl, cats hiss, apes beat their chest or wave sticks about.
Niko Tinbergen called these Fixed Action Patterns [FAP]
What are the 5 features of FAPs or fixed action patterns?
Lea [1984] analysed FAPs and identified 5 features:
Stereotyped – behavior follows a certain pattern each time.
Universal all the animals in that species use the same type of threat.
Innate: all the animals in that species seem to be born with it and don’t have to learn it.
Ballistic: Once it starts it cannot simply be stopped.
Specific triggers seem to set it off.
How did breland support the use of fixed action patterns?
Breland and Breland found that animals tend to revert to instinctive behavior regardless of training. This would support the FAP theory.
How is the environmental influence on behaviours a limitation of fixed action patterns?
It could be argued that some behaviors are learned in the environment – but maybe not all. Dogs can been trained by hunters, army and police to act in particular ways. Ethology sais its genes.
How do Faps or fixed action patterns have bad temporal validity?
Eibesfeldt (1972) tried to identify human FAPS such as smiling to show non-aggression, however he found that our culture changes so quickly that cultural differences in signs can change more quickly than evolutionary patterns. Rude words and hand signs can change, so not evolutionary. Humans are certainly capable of developing new ways of expressing aggression – such as cyber bullying!
What are innate releasing mechanisms?
Creatures have evolved an instinctive response to certain signs. [Like a red rag to a bull!]
Eg. Male sticklebacks will respond aggressively to the red underbelly of a rival male – but not to a female who does not have the red underbelly.
What is the hydraulic model of fixed action patterns?
Lorenz said that all creatures build up a reservoir of Action Specific Energy – you could call it “pent up aggression”. When the Innate releasing mechanisms [IRM] trigger the Fixed Action Pattern [FAP] all the aggression is fired off.
Once it is out of the system the animal is less aggressive again till the level of Action Specific Energy has built up again.
How does the hydraulic theory of fixed action patterns have support from Freudian psychology?
This explanation was probably an example of Lorenz trying to adapt Freudian ideas to animals! Freud wrote about the build-up of sexual energy [Libido] and Lorenz applied a similar idea here.
How does the hydraulic explanation of fixed action patterns fail to fully explain aggression?
This theory fails to explain premeditated aggression and bearing grudges.
Who’s study found the opposite of “venting” anger?
Holst [1954] found that instead of getting it out of the system , aggressive action could feed back to make the person more angry and increasingly more aggressive.
What did Arms find about venting anger and the idea of catharsis in hydraulic explanation of fixed action patterns?
Arms et al. [1979] found that watching violent sport did not flush aggression out of the system but tended to increase it. Bushman does not agree with idea of Catharsis – says that aggression may lead to more aggression.
Who identified aggression as adaptive and what are the 7 stages he found?
• David Buss has identified 7 adaptations of aggression in humans:
1 Self Defence
2 Reputation to ward off future aggression
3 To achieve status – more allies less enemies
4 Get and keep better share of resources. Pinker (1997) states aggression evolved in men to compete for women. This may have been the MAIN reason for aggression as there was no other property worth fighting over as we evolved.
5 Deny own resources to children of rivals
6 To prevent other males sharing the prime females
7 Prevent partner being unfaithful. For example, sexual jealousy may have evolved to ensure that men pass on their own genes rather than allowing other males access to their mate.
Who proposed inter group aggression what is it and what are the 5 cognitive requirements, and who adapted it?
This is aggression between different groups, such as warfare and gangs.
• Buss states human males have evolved cognitive bias towards organised aggression: E.g.
1 Cognitive bias to expect attack
2 Cultivating tough reputation
3 Use of vengeance as a deterrent
4 Strategies for planning and timing an attack
5 Deception and the ability to detect deception
• Cosmides and Tooby, the Military Contract: Men will only fight if those who share the rewards also share the danger. Other animals are not bright enough to work this out.
What is intra group aggression and what 4 studies can be used as a01? (young men, evolve competition, land + jealousy, control)
This is aggression within a single group, mainly linked to male rivalry and sexual jealousy.
• Daly and Wilson: Male – Male aggression among young men is common in all human cultures – suggesting it is evolutionary.
- Pinker (1997) suggests aggression evolved in men to compete for women. This may have been the MAIN reason for aggression as there was no other property worth fighting over as we evolved. Through most of evolution there was no money, no real property, so women were the only target of aggression.
- Potts and Hayden (2008): War and aggression aimed to control women’s mating habits since development of farming made inheritance of land important. Jealousy has evolved as a male response to the threat of infidelity. Jealous males are determined to pass on their OWN genes.
- Daley and Wilson (1988): Men may use jealousy and violence to control partners sexual behavior Violence is not intended to kill but may have that result. E.g. Fertile young women 10 times risk of domestic violence.
How is the evolutionary research criticised on fact of ethics?
Ethics: Waller says : Violence , Xenophobia and even genocide are adaptive, but this is very deterministic and unethical.
