Aggression Flashcards
What is the definition of aggression?
An act carried out with the intention to harm another person
What is the definition of proactive aggression?
A planned method - less emotional e.g teasing
What is the definition of reactive aggression?
Angry and impulsive aggression, accompanied by physiological arousal e.g. temper tantrum
What is the definition of neural mechanisms?
Areas of the brain and their communication, and how they may be responsible for aggression
What is the definition of hormonal mechanisms?
Chemical substances circulating in the bloodstream - responsibility for aggression?
What is the limbic system explanation for how aggression is caused?
Amygdala: evaluates emotional importance of sensory info -> assesses and responds to environmental threats -> (hippocampus: involved in the formation of LTM -> compared current threat to past experiences -> if impaired, sensory info cannot be put into context) -> more likely to interpret sensory information as a threat -> reactivity increases accordingly -> greater reactivity = greater aggression.
What is the serotonin explanation for aggression?
- Serotonin = inhibitory transmitter -> normal levels means reduced neuron firing, inhibiting response to emotional stimuli, so associated with self control.
- Normal serotonin levels will therefore inhibit the firing of the amygdala.
- Low serotonin levels remove inhibitory effects, making people less able to control aggressive behaviour, making aggression more likely.
What case study is supporting evidence for the limbic system (CW)? What is the counterargument?
Support:
- Charles Whitman shot 13 people at Texas College after killing his wife and mother.
- Left a note asking doctors to examine his brain because he thought something was making him aggressive.
- Doctors found a tumour pressing against his amygdala, supporting its role in aggression.
Counterargument:
- Charles Whitman was raised in a home with guns (could have learnt aggressive behaviour) and was going through stress (breakdown of marriage + failing uni) and was suffering childhood trauma (abuse from father) so cause and effect cannot be established here.
What is a weakness of both the limbic system and serotonin? What is the counterargument for this?
- Neural explanations are overly determinist as they suggest our behaviour is caused by internal biological processes which we have no control over - implications for principle of legal system.
- Could lead to need to screen people and discriminate based on their results.
- Makes it harder for the victims as the offender cannot take responsibility, may invade their privacy, big ethical issues!
- Does not make the theory less valid, only less palatable.
Counterargument: If people could be screened and therefore know they are vulnerable, they could avoid environmental stimulus or develop coping mechanisms.
What is supporting evidence for the serotonin explanation? What is a weakness of this study?
- Raleigh et al.
- Studied importance of serotonin on aggressive behaviour in monkeys.
- Found that monkeys who had diets which increased serotonin production had decreased aggression, and vice versa.
- This supports a causal link, supporting the study’s internal validity.
Counterargument: - Issues with generalising from animal studies to humans - aggression may be different as animals cannot consider consequences.
What is the testosterone hormonal explanation for aggression?
- male sex hormone testosterone is responsible for development of masculine features and regulating social behaviour (with its influence on certain areas of the brain associated with aggression)
- It is thought higher testosterone levels are linked with aggressive behaviour.
- E.g. Dolan et al. Found that there was a positive correlation between testosterone levels and aggressive behaviours in male offenders.
What is the progesterone hormonal explanation for aggression?
- female ovarian hormone thought to impact female aggression.
- levels vary with the menstrual cycle, highest during and after period.
- low levels linked to increased aggression in women.
What is the supporting evidence for the progesterone explanation of aggression? What is the counterargument?
Ziomkiewica et al. Found a negative correlation between progesterone and self-reported aggression, supports link.
Counterargument: cannot determine cause and effect.
What supporting evidence for the testosterone explanation (hormonal) of aggression? ( Dabs et al.)
- Dabs et al. Measured salivary testosterone in violent and non-violent criminals.
- Found that those with high testosterone levels had a history of primarily violent crimes, supporting the link between testosterone and aggression.
What is supporting evidence for testosterone? (Giammanco et al. Animals)
- Giammanco et al. Found that increasing the testosterone levels in animals caused increased aggression levels and vice versa.
- supports internal validity, establishes cause and effect.
How can the MAOA gene cause aggression (genetic explanation)?
- MAOA is an enzyme which regulates the metabolism of serotonin in the brain.
- The gene responsible for producing this enzyme has been associated with aggressive behaviour.
- A low activity variant (allele) of this gene leads to low activity of MAOA in certain areas of the brain, and has been linked to aggression.
What is the supporting study for the MAOA gene as a genetic explanation of aggression?
- Brunner et al.
- Studied a large Dutch family involved in aggressive criminal behaviours such as rape.
- Found that they all had abnormally low levels of MAOA in their brains, and the low-activity MOAO gene.
How do twin studies work for studying aggression?
- Study pair of twins (MZ or DZ) where one has been found to be aggressive.
- Measure the concordance percentage.
- If aggression is fully genetic, the concordance will be 100%. If it is partly genetic, the concordance rate for MZ twins will be higher than DZ twins.
How do adoption studies work for studying aggression?
- Study people who are aggressive who were adopted as children.
- Study biological + adoptive parents to see if either are aggressive.
- If aggressive is genetic, at least one biological parent should be aggressive.
What supporting evidence is there for MAOA as the cause of aggression? (Money game)
- Mertins et al.
- Study of participants with high and low variants of the MAOA gene in a money-distributing game.
- Participants could choose whether or not to contribute money for the good of the group.
- Males with the higher activity gene were more cooperative and made less aggressive moves than those with the low-activity gene.
What is a weakness of twin and adoption studies as supporting evidence for the genetic explanation?
- Many are focusing on studying those convicted of violent crime is problematic
- many who commit violence are never convicted for it.
- those convicted of a violent crime may have never done one before, explaining why a link may not be found in these studies.
- studies are not externally valid and may underestimate the link between genes and aggression
What is a strength of the genetic explanation? (Gender differences)
- The MAOA gene theory can explain gender differences for aggressive behaviour, as the gene may be linked to the X chromosome.
- Women have two X chromosomes, whereas men only have one.
- When women inherit a faulty X chromosome, it it okay because they have another normally functioning one to compensate/dominate.
- When men inherit this chromosome, they have no other to compensate.
What is a weakness of the genetic explanation of aggression? What is the counterargument for this?
- Determinism - implications for legal system and wider society, may result in a need for genetic screening.
- Theory should be treated with caution unless we are sure it is absolutely correct.
- Counterargument: if people know they have a predisposition for aggression due to genetics, they can develop coping techniques and avoid environmental stimuli.
What is the definition of ethology?
The study of animals in natural settings - the findings are then generalised to humans because we all experience natural selection.
What is the definition of natural selection?
The process through which living organisms survive and adapt, as organisms better suited to the environment survive and reproduce.
What is the definition of adaptive?
Beneficial for survival, allowing an animal to stay alive and reproduce.
What is the definition of conspecifics?
Members of the same species
What is the definition of innate releasing mechanisms?
hard-wired networks of neurons in the brain that respond to an environmental stimulus (a sign or releaser such as a facial expression) by initiating a fixed action pattern.
What is the definition of fixed action patterns?
A set sequence of behaviours (in this case, aggression) which are stereotyped to occur only in specific conditions and do not require learning (i.e. they are innate).
What is the definition of cuckoldry?
the man raises an offspring that is not his own and so contributes to the survival of a rival’s genes and is left with fewer resources to invest in his own offspring in the future.
What is the definition of mate retention strategies?
Ways males retain their mates and try to deter them from sexual infidelity.
What is the definition of sexual jealousy?
An emotional response to the threat of infidelity - serves to motivate mate guarding etc.
What is ritualistic aggression (ethological explanation)? How is it adaptive?
- Aggression carried out in a set order.
- Threat displays: bearing teeth, hitting chest etc.
- Adaptive: allows competitors to assess relative strength before escalating a conflict, making the opponent back down instead of costly aggression, allowing for the survival of the species.
What did Lorenz point out about ritualistic aggression? How is it adaptive?
- Aggression between co-specifics ends with ritual appeasement displays signalling defeat e.g. wolves exposing their jugulars.
- signal of defeat inhibits further aggression, preventing death and so ensuring the survival of the species.
How is aggression adaptive by the dominance hierarchy explanation?
- Dominance hierarchies are established where the winner climbs the social ladder.
- Increased status leads to better choice of mates and more access to resources.
- Therefore adaptive because increased access to resources and mates means that it is naturally selected.
How is aggression explained by the territory explanation?
- The defeated animal normally establishes territory elsewhere instead of being killed.
- This means that the winner has less competition for resources in their area (less competition for food).
- Furthermore, animals being spread out means there is a reduced chance of them all starving.
- There aggression is adaptive as it aids survival and so is naturally selected.
What does the ethological explanation suggest about innate aggressive behaviour?
That it is mostly genetically determined, and therefore is adaptive (passed down for survival).
According to Lea, what are the six main features of fixed action patterns?
- Stereotyped - unchanging sequence of behaviours
- Universal - same in every member of the species
- Unaffected by learning - same for every member of species regardless of learning.
- ‘Ballistic’ - Follows an inevitable course once triggered which cannot be altered before it is completed.
- Single-purpose - only occur in a specific situation and not any others
- Response to specific identifiable sign stimulus (or a releaser if between conspecifics).
How are fixed action patterns triggered.
Environmental stimulus -> innate releasing mechanism -> fixed action pattern.
What was the procedure of Tinbergen’s 1951 study?
- During mating season male sticklebacks are a highly territorial bird, and develop a red spot on chest. If another male enters their territory in this period, a fixed action pattern is initiated. Sign stimulus (red spot) -> triggers the innate releasing mechanism.
- Tinbergen presented male sticklebacks with a series of differently shaped wooden models, some with a red spot on their underbelly and some without.
What were the findings of Tinbergen’s 1951 study?
- Regardless of shape, the male stickleback aggressively display if the model had a red spot. No red spot, no aggression.
- The FAPs were unchanging from one encounter to another, and always ran their course to completion once triggered.
What is the undermining evidence for the ethological explanation? (Nisbett)
- Nisbett found that there was a north-south divide in homicide rates in the U.S. with it being much more common in white males from the south.
- He found in a lab study that when southern males were insulted, they were more likely to become aggressive than northern males.
- Nisbett concluded this was due to learnt social behaviour which calls into question the validity of the explanation as it suggests that culture can override innate influences - not a complete explanation.
What is the supporting evidence for the ethological explanation of aggression? (Crossover)
- Brunner et al. Found that a low activity variant of the MAOA gene is closely associated with aggression.
- Research on the limbic system also suggests there is an innate releasing mechanism for aggression in human brains.
- Supports the validity of the explanation.
What is supporting evidence for the ethological explanation of aggression? (Anthropology)
- Anthropolical research suggests that there is ritualistic aggression present in human cultures.
- For example, Hoebel found that among Innuit eskimos, song duels are used to settle grudges and disputes.
- Supports that animal studies are generalisable to humans, as ritualistic aggression is also used by humans.
What is undermining evidence for the ethological explanation of aggression? (Goodall)
- Observation of chimpanzees in Tanzania.
- During a war, chimpanzees systematically attacked each other in a premeditated way, and on one occasion a chimpanzee was held down and bitten for 20 minutes.
- These attacks all occurred despite signs of appeasement, but these did not stop the aggression. This, combined with the fact that the killing was systematic, calls into question the validity fo the ethological explanation of aggression.
What are the six key words to use when talking about evolutionary explanations of human aggression?
- Adaptive
- Survival
- Reproduction
- Natural selection
- Aggressive genes get passed down
- Aggression becomes more widespread in the population
What is the sexual jealousy explanation of aggression? (Overview)
- Male aggression is motivated by jealousy to ensure their own paternity and genetic success.
- Men have paternity uncertainty because of the threat of cuckoldry.
- Men who avoid cuckoldry in the past have been more reproductively successful, so male aggressive strategies evolved to help retain their mate and deter them from sexual infidelity.
