biological explanations of aggression

Question 1

what does the limbic system mean?

Answer 1

buried deep within the brain a network of structures called the limbic system.

Question 2

what did James papez and Paul Maclean identify for the limbic system

Answer 2

they identified the LS as compromising the cingulate gyrus, septal area, hypothalamus, fornix, amygdala + parts of the hippocampus + thalamus.
Most important - amygdala.

Question 3

what does the amygdala predict

Answer 3

an important predictor for aggressive behaviour

Question 4

what was Katarina Gospic et al laboratory method called?

Answer 4

Ultimatum game - assessed aggressive behaviour.

Question 5

Procedure of Ultimatum game (Katarina Gospic)

Answer 5

-Features two players
-the proposer offers to split money in a certain way with the responder.
- if the responder accepts, the money is split .
-but if rejects both receive nothing.
-partcipants played as repsonders had their brain scanned by fmri, which highlights activity in different areas on the brain.

Question 6

findings of ultimatum game (Katrina Gospic)

Answer 6

when respondents rejected unfair offers scans revealed a fast + heightened response by the amygdala.
also found that benzodiazepine drug (reduces arosal of automatic nervous system) taken before the game had two effects on respondents offers:
-halved number of rejections
-decreased the activity of amygdala.
this strong evidence of an association between reactive aggression + amygdala activity.

Question 7

what is serotonin?

Answer 7

Is a neurotransmitter involved in communication of impulses between neurons. it has widespread inhibitory effects on the brain; slows down + dampens neural activity.

Question 8

what are normal levels of serotonin linked with?

Answer 8

N levels of S in orbital context linked with reduced firing of neurons + this is associated with greater degree of behavioural self-control.

Question 9

what do decreased levels of serotonin do

Answer 9

D S may disturb this mechanism, reducing self control + leading to an increase of impulsive behaviour including aggression. (denson et al)

Question 10

what did Matti virkkunen et al do in relation to serotonin.

Answer 10

compared levels of serotonin breakdown product (5-HIAA) in the cerebrospinal fluid of violent impulsive + violent non-impulsive offenders.
The levels were significantly lower in the impulsive offenders + they suffered from more sleep irregularities.
significant - serotonin regulates sleep patterns. supports the role of serotonin in reactive aggression.

Question 11

hormonal mechanism of aggression - testosterone males and females intro

Answer 11

men generally more aggressive then women. attention focused on male sex hormone testosterone responsible for the development of masculine features.
also has role in regulating social behaviour via its influence on certain areas of the brain implicated in aggression.

Question 12

animal studies in relation to hormones for aggression + researcher:

Answer 12

Giammonco et all 2005
demonstrated experimental increases in testosterone are related to greater aggressive behaviour in several species.

Question 13

hormonal mechanisms in aggression
test one studies: prison offenders research + researcher

Answer 13

Violent offenders: Married Dolan et al
found a positive correlation between testosterone levels + aggressive behaviours in sample of 60 male offenders in UK maximum security hospitals.
Most these men suffered from personality disorders like psychopathy + had history of impulsively violent behaviour.

Question 14

Evaluation of neural mechanisms in aggression

Answer 14

• alternative explanations:
  Emil coccaro et al (2007) patients with psychiatric disorders the prominent feature of aggression, activity in the OFC is reduced, disrupting its impulsive control function + leading to increased aggression.
  Gospic et al (2011) indicated that aggression the regulation of aggression involved 3 neural structures in the brain: the amygdala, OFC + connection between the two.

-research support:
Mitchell German et al (2009): effects of drugs on serotonin. gave ps placebo drug or dose of paroxetine (enhances serotonin). P then took part in lab based game which gave electric shock varying in intensity.
Paroxetine group gave fewer + less intense shocks than placebo group.
however only true for those with history of aggression. Means- gave useful evidence of link between serotonin function + aggression goes beyond usual correlational findings.

Question 15

evaluation of hormonal mechanisms of aggression

Answer 15

-research support
Allan Mazur formulated biosocial model of status (BMoS) explains link between test + aggression in humans.T levels change rapidly during day especially repsonse to social interactions related to status (competition). CHange in test levels following loss of status should affect post-competition aggression.

-further research support
evidence of link with T + aggression in humans is mixed.
Carre + Mehtas dual hormone hypothesis
claims high levels of cortisol are low. when C is high testorone levels blocked.
C is glucoocorticoid hormone that plays central role in stress response.
Popma study supports this
Comined activity of test and cortisol may be better predictor of human aggression than either hormone alone.

Question 16

list all the genetic factors in aggression

Answer 16

-twin studies
-adoption studies
-the MAOA gene
gene-enviorment (GxE) interactions

Question 17

genetic factors in aggression:
twin studies

Answer 17

-suggests that heritability accounts for 50% of variance in aggressive
-EMil coccaro et al studied male monozygotic + dizygotic twins. MZ twins share 100% of their genes but DZ share 50%
For aggressive beh e.g. physical assault found concordance rates of 50% for MZ twins + 19% for DZs. corresponding figures for verbal aggression were 28% MZ + 7% DZ.

Question 18

Genetic factors in aggression:
who divides the adoption studies

Answer 18

Soo Rhee + Irwin Waldman (2002)

Question 19

genetic factors in aggression:
what was adoption studies

Answer 19

similar with biological parents = genetic influence
similar with adopted parents = suggest environmental influence
Rhee + Waldman meta-anaylisis of direct aggression + antisocial behaviour.
Findings= genetic influences accounted for 41% of variance in aggression similar to twin studies

Question 20

Whats the MAOA gene
(genetic factors In aggression)

Answer 20

is an enzyme.
role to ‘mop up’ neurotransmitters in the brain after nerve impulses has been transmitted from one neutron to another.
breaks down the neurotransmitter esp serotonin into constituent chemicals to be recycled.
Disfunction of this leads to abnormal activity which affects level of serotonin in the brain.

Question 21

what’s the warrior gene?
(genetic)

Answer 21

variant of MAOA gene, leads to low MAOA activity in brain. been associated with aggressive behaviour.

Question 22

what was Han Bruner and Gregory Stuart et al studies (MAOA)

Answer 22

Brunner et al: studied 28 males of dutch family repeated involved in impulsively aggressive violent criminal behaviour e.g. rape, attempted murder, physical assault.
findings = had anomaly low levels of MAOA + low activity version of MAOA gene.

Stuart et al: studied 97 men involved in inflicting intimate partner (IPV) violence, part of battery treatment programme.
findings= men with low-activity MAOA gene found to be most violent of IPV + inflicted worst injuries on partners

Question 23

what’s the gene-environment (GxE) interactions
(genetic factors in aggression)

Answer 23

says that low MAOA gene activity is only related to adult aggression when combined with early traumatic life events

Question 24

what’s the study for gene-environment interactions + who

Answer 24

Frazzetto et al
found association between higher levels of antisocial aggression + low MAOA in adult males. - only the case for those who experienced significant trauma during 1st 15 years of life e.g. sexual abuse. Those who hadn’t didn’t have partially high levels off aggression as adults even if they had low MAOA.
shows= evidence of gene-enviorment interaction.

Question 25

evaluation of the genetic factors in aggression A02

Answer 25

-questions reliability:
difficult to establish how influential genes r in aggression. Because difficult to separate genetic + environmental factors.
example: McDermott et al showed Ps with low activity MAOA gene behaved aggressively in lab based money allocation game but only when provoked. Otherwise- no more or less aggressive than other Ps.

-multiple genetic factors: other genes involved in aggression. Stuart et al (IPV) study in men associated not just MAOA but also serotonin transporter gene. most likely combination of 2 genes closely linked with IPV.

-different methods of measuring aggression in studies. Incls, self-reports, parent + teacher reports, direct observation. If research finding vary depending upon how aggression is measured, then becomes difficult to draw valid conclusions about role of genetic factors.

-research support
-non-human animal studies
hypothesis that MAOA gene plays role in aggression originated with mice research. Godar et al showed MAOA knockout mice have significantly increased brain serotonin levels + are hyper aggressive.

Question 26

list all the ethological explanations of aggression A01

Answer 26

-adaptive functions of aggression
-ritualistic aggression
-innate releasing mechanisms + fixed action patterns
-key research into IRM + FAPs

Question 27

what’s the adptive function of aggression
(ethological)

Answer 27

-suggest main function of aggression is adaptive.
-benefical to survival ‘defeated’ animal is rarely killed but forced to establish terrirotory elsewhere.
- means: species spread out over a wide area + discover resources in different place, which reduces competition + possibility of starvation.
-establishes dominance hierarchies.
-male chimpanzees use aggression to climb social hierarchy.
-dominace gives special status.
-happens in humans too.

Question 28

what’s the adaptive functions of aggression study
(ethological)

Answer 28

Pettit et al (1988) studied play groups of young human children.
-observed how aggression played an important role in the development of some children’s dominance over others bring benefits.
e.g. access to resources + getting their own way.

Question 29

what’s the ritualistic aGGRESSION
(ethologicaL)
(Lorenz’s early observation)

Answer 29

(ritual series of behaviour carried in set order).

Lorenz early observations of fights between animals of the same species was how little actual physical damage was done.
Most aggressive encounters- period of ritualistic signalling + rarely reached point of becoming physical.
Also- Lorenz pointed out that intra-species aggressive confrontations end with ritual appeasement displays. INdicate acceptance of defeat + inhibit aggressive behaviour in victor, prevents damage to loser.

example: wolf exposes neck to victor.
Adaptive because, if every aggressive encounter ended with death this could threaten existence of species.

Question 30

what’s examples of ritualistic signalling
this is also the examples in Lorenz early observations of animals

Answer 30

-displaying claws
-teeth
-facial expressions of threat

Question 31

what’s innate releasing mechanism + fixed action patterns
(ethological)

Answer 31

Innate releasing mechanism = built in physiological process or structures.
e.g. network of neutrons in the brain.

Environmental stimulus triggers the IRM which then releases fixed action pattern.

Question 32

(ethological)
what’s the fixed action pattern + which psychologist created it?

Answer 32

Stephen Lea (1984) identified 6 features:
1. stereotyped or relatively unchanging sequence of behaviour
2. universal because the same behaviour is found in every individual species
3. unaffected by learning the same for every individual regardless of experience
4. ‘ballistic’ once the behaviour is triggered it follows course + can’t be altered before its completed.
5. single-purpose the behaviour only occurs in specific situation + not any other
6. a response to an identifiable specific sign stimulus

Question 33

what’s was the key research into IRMs + FAPs
(ethological)

Answer 33

procedure: male sticklebacks r highly territorial during spring mating season, also develop red spot on their underbelly.
if another male enters their territory sequence of highly stereotyped aggressive behaviour occurs. Sign stimulus triggers the innate realsing mechanism - red spot.
Niko tinbergen (1951) presented sticklebacks with wooden models of different shapes.

Findings: regardless of shape if model had red spot stickleback would aggressively display + attack it. if no red spot- no aggression. T also found these aggressive FAPs were unchanging from one encounter to another. once triggered the FAP always ran its course to completion without any further stimulus.

Question 34

ethological explanation evaluation A02

Answer 34

-research support
bruner et al MAOA gene associated with aggression. suggesting innate basis.

-cultural difference in aggression
Nisbett (1993) found- north south divide in US for homocide rates. Killing more common amongst white males in southern states than northern states. only true for reactive aggression triggered by arguments, N concluded difference cause by ‘culture donor’ = learned by social norm.
further supported by Nisbett et al lab study. found: when white males in south were insulted in research they were more likely than northern males to become aggressive.

-evidence against ritualistic aggression
Jane Goodall (2010) chimpanzees at Gombe stream national park in Tanzania. during ‘four year war’ male chimps from one community systematically slaughtered all the members of another group. Did this in co-ordinated + premeditated fashion. violence continued despite the victims offering signals of appeasement + defencelessness.

-unjustified generalisation to humans
lots of animal studies; lorenz tinberg

Question 35

list all the evolutionary explanation of aggression A01

Answer 35

evolutionary explanation of sexual jealousy
evolutionary explanation of bullying

Question 36

Give explanation of sexual jealousy in men
(evolution)

Answer 36

sexual jealousy is a major motivator of aggression in males
reason why: unlike women men can never really know if they’ve truweky fathered a child. This uncertainty is result of the threat of male cuckoldry or having to raise other spring that’s not their own. Any investment in offspring that’s not their genes is waste waste of their resources.
- men in evolutionary past who could avoid cuckoldry were more reproductively successful.
psychological mechanism has evolved to increase anti-cuckoldry behaviour in males.
e.g. sexual jealousy more strong in males than females. created aggressive strategies to retain partners + prevent straying.

Question 37

what are the adaptive mate retention strategies + who

Answer 37

Wilson+ Daly (1996)
-direct guarding: male vigilance over partners behaviour.
e.g. checking who they’ve been seeing, coming home early, keeping tabs on their whereabouts, tracking apps.
-Negative inducements: insulting threats of dire conseuqnce for infidelity e.g. kill myself if I leave.

this behaviour linked to violence. women who reported this in their partners were twice as likely to have suffered physical violence.
-73% required medical attention
-53% said they feared for their lives.

Question 38

what was the study of intimate partner violence + which psychologist?
(evolutionary)

Answer 38

Todd Shackelfold et al (2005)
procedure: men + women in 107 married couples completed different questionnaires. All married less than 1 year. men- completed mate retention inventory, assed mate retention behaviours.
women- spouse influence report measured the exert of their partners violence in their relationship.
Findings: strong positive correlation between men + women reports. = men who used mate mention strategies more likely to use physical violence.

Question 39

what’s the evolutionary explanation of bullying

Answer 39

bullying occurs from power imbalance.
researchers have traditionally view bullying maladaptive behaviour, e.g. result of poor asocial skills or childhood abuse.
evolutionary ancestors may use bullying as an adaptive statergy to increase survival by promoting their own health + creating oppotunities for reproduction.

Question 40

what was Volk et al (2012) evolutionary of bullying

Answer 40

argue characteristics associated with bullying behaviour are to attractive to oppposite sex.
Males: suggest dominance, acquisition of resources + strength.also benefit of warding off potential rivals.
TF- such behaviour would be naturally selected because males would have greater reproductive success.

Female bullying: used in relationship as method of control. use bullying to secure partners fidelity = they continue to provide resources for future offspring . Again naturally selected for reproductive success.

Question 41

Evaluation of evolutionary explanations of human aggression
(A02)

Answer 41

-Research support for aggression + sexual jealousy
Shackelford et al (2005)
indicates clear link between greater risk of infidelity + cuckoldry + aggression. supports predictions derived from the evolutionary explanation concerning adaptive value of aggression

-evolutionary explanations account for gender differences

-real-life applications
bullying- help create anti-bullying interventions. Rigby (2010)established several interventions based on bullying is maladaptive behaviour, can be eridicated by addressing bullies perceived deficiencies.

-cultural differences
Ikan San: aggressive behaviour is discouraged from childhood + therefore rare. those who do use it find their status + reputation within the community are diminished.