Aggression

• Papez and Maclean - neural mechanisms


  Linked the lambic system to emotional behaviours, including aggression. They defined the limbic system as the hypothalamus, amygdala and parts of the hippocampus.
• Denson - orbits frontal cortex and serotonin


  Decreased serotonin disrupts a mechanism ( firing neurons) , reducing self control and increased levels of impulsive behaviour and aggression.
• Virkkunen - orbitofrontal cortex and serotonin 


  Compared levels of a serotonin break down product (called 5-HIAA) in the cerebrospinal fluid of violent impulsive vs violent non-impulsive inmates. Found lower levels in impulsive offenders, meaning they had lower levels of serotonin
• Giammanco - testosterone animal study


  Castration in animal studies, reduces aggression in male species. Giving injections of testosterone to the castrated animals restores the aggressive behaviour.
• Ziomkewicz - progesterone

  Found a negative correlation between progesterone levels and self-reported aggression. Low levels are associated with aggression in women.
• Coccaro - twin studies, genetic factors in aggression


  For aggressive behaviour (physical assault), found concordance rates of 50% for MZ twins, 19% for DZ twins. For verbal aggression, concordance rates of 28% for MZ twins and 7% for DZ twins.
• Rhee and Waldman - adoption studies into aggression


  Meta-analysis of adoption studies of direct aggression and antisocial behaviour. hey found that genetic influences accounted for 41% of the variance in aggression, similar to the twin studies.
• Lea and Chambers - MAOA-L (low activity)in Maori


  The MAOA-L variant was possessed by 56% of Maori, where only 34% of Caucasian people have it. Historically, Māori are known to be warriors
• Brunner - MAOA-L variant study


  Studied 28 men from a large Dutch family who were involved in impulsively aggressive violent criminal behaviour such as rape, attempted murder and psychical assault. These men had low levels of MAO-A and possessed the gene MAOA-L.
• Frazzetto - gene and environment interactions


  Found an association between higher levels of antisocial aggression and the MAOA-L gene variant in men. However, this only counted for people who had experience significant trauma such as physical abuse during the first 15 years of their life. Even if p’s had the MAOA-L variant, didnt have high levels of aggression nor experienced childhood trauma. (Diathesis stress model)
• Tinbergen’s research - ethological explanation

  Male sticklebacks are a very territorial fish, during mating season they have a red spot on their belly. When an another male enters their area, a sequence of stereotypes aggressive behaviours start (FAP). Findings - regardless of shape, if the object had a red spot underneath, the male stickleback would attack it. No red = no aggression even when model was realistic. FAPs didnt change and always ran to completion.
• Wilson and Daly - male retention strategies

  • Direct guarding, male vigilance over their partner e.g checking who they have been seeing, tracking them
  • Negative inducements, ‘I’ll kill myself if you leave me’
• Wilson - physical violence against partners


  Asked women to report mate retention strategies in their partners e.g ‘ he insists on knowing who you are with and where you are at all times’. Women who agreed with such statements were twice as likely to have experienced physical violence from their partners. Of these women, 73% required medical attention, and, 53% feared for their lives. Evidence that mate retention strategies link to physical violence.
• Volk - evolutionary explanation of bullying


  Argues that characteristics associated with bullying behaviour are attracted to females such as dominance, acquisition of resources and strength. Bullying also wards of potential rivals, therefore bullying would be naturally selected because these males would have greater reproductive success.
• Sapolsky 


  adolescent boys who gain a reputation for being tough and less likely to experience aggression themselves as other boys avoid contact with them. This benefits their health as those at the top of a dominant hierarchy experience less stress.
• Campbell - female bullying


  Women use bullying behaviour to secure partners fidelity ( to provide a resources and future offspring). Such behaviour would be naturally selected because of enhanced reproductive success.
• Dollard

  Frustration-aggression hypothesis
• Berkowitz - weapon effect


  Frustration mainly creates a readiness for aggression.

  Berkowitz and LePage - participants were given real electric shock by Confederate, creating anger and frustration. Participants had the opportunity to shock them back, aggression was higher when there was two guns on the table versus when there was no guns on the table.
• Geen - research on frustration-aggression

  Male university students completed a jigsaw puzzle. Frustration levels were manipulated in three ways.

  • A Confederate kept on interfering
  • Confederate insulted participants as they failed to solve the puzzle
  • The puzzle was actually impossible to solve

  They later could shock the confederates (not real). Insulted Ps gave strongest shocks on average, followed by the interfered group, then the impossible task. However, all selected more intense shocks than a non-frustrated control group.
• Bandura BOBO DOLL


  Young children observed an adult model assaulting the Bobo doll. Aggressive behaviours, such as throwing kicking Were accompanied with verbal outbursts, such as ‘ sock him in the nose!’. Children were frustrated by being in a room of toys, but not being able to play with them. Many children imitated the behaviour Very closely. Boys imitated physical aggression more than girls, but no difference between verbal aggression. Boys were more likely to imitate the same-sex model than girls. Control group, so no aggression and did no aggression
• Zimbardo - Deindividuation

  De individuated behaviours are emotional, impulsive, irrational, disinhibited, and anti-normative -> Lots of self-awareness and ignores social norms. In an Individuated state behaviour is rational and normative.
• Dixon and Mahendran 


  Anonymity shades crowd behaviour. We have less fear of retribution because we are unidentifiable and part of a faceless crowd, the bigger the crowd, the more anonymous we are and people are less likely to judge us negatively
• Prentice-Dunn and Rogers - reduce self-awareness


  Two types of self awareness

  • Private self awareness, concerns how we pay attention to our own feelings and behaviours which is reduced when we are part of a crowd. We are less self critical and less thoughtful promoting a Deindividuated state.
  • Public self awareness, how much we care about what other people think of our behaviour, also reduces in crowds. We no longer care how people see us so we become less accountable for our aggressive actions.
• Dodd - research on de-individuation


  229. Undergrad psychology students Were asked the question ‘ if you could do anything humanly possible with complete assurance that you would not be detected or held responsible, What would you do?’

  3 Independent raters, unaware of hypothesis decided word categories. Findings -> 36% Involved anti Socal actions. 26% were actual criminal acts, most commonly rob a bank. Students said murder and rape, only 9% with prosocial behaviours, such as helping people. Evidence for a link between anonymity, de-individual ion and aggression
• Irwin and Cressey - prisons


  Importation model, aggression in prison is due to the disposition of the criminals
• DeLisi


  Study the group of juvenile offenders in Californian institutions who had negative backgrounds such as childhood trauma. These individuals were importing these characteristics into prison. The research is compared this group with a control group of inmates who did not have these negative features. Inmates with negative backgrounds were more likely to engage in suicidal activity, sexual conduct and acts of physical aggression.
• Clemmer 


  Deprivation model - aggression in prisons is due to the harsh conditions of the prison and have no freedom which is detrimental to their mental health
• Steiner - situational explanation deprivation model

  512 US prisons, investigating predicting factors of aggression. Inmate-on-inmate violence was more common in prisons, whether there was a higher proportion of females staff, overcrowding and more inmates in protective custody.
• Robertson - effects of TV


  Measured the TV viewing hours of over 1000 New Zealanders at regular intervals up to the age of 26 years old. Found that more time watching TV in childhood and adolescence was a reliable predictor of aggressive behaviour in early adulthood E.g violent crimes. Watching more TV is also associated with the reduced social interaction and poor educational achievement, therefore the link between aggression and excessive viewing maybe indirect
• Bandura - violent film content


  Looked at the effects of aggression viewed on screen. Replication of the Bobo doll, and the adult model was beating the doll.
• Paik and Comstock - TV effects aren’t strong 


  meta analysis of roughly 200 studies, found a positive correlation between TV violence and antisocial behaviour. However, they estimated that TV violence only accounted for between 1% and 10% of the variance in children’s aggressive behaviours. Watching TV has a relatively minor role in causing aggression.
• Bartholow and Anderson - computer games


  lab experiment, used a measure called the Taylor competitive reaction time task (TCRTT). Participants delivered blasts of white noise at chosen volumes to punish (non-existent) opponents. Found that students who played a violent computer game (Mortal Kombat) for 10 minutes selected significantly higher volumes of white noise than students who played a nonviolent golfing game (PGA tour)
• Weisz and Earls - role of desensitisation 


  A lab experiment, where they showed participants a clip of the film straw dogs which contained a prolonged and graphic rape scene. Participants then watched a re-enactment of a rape trial. Male viewers of the movie Showed greater acceptance of rape myths and sexual aggression, Also expressing less sympathy for the victim of the trial. This effect was non-existent with female participants.
• Dolan - testosterone


  Found a positive correlation between testosterone levels and aggressive behaviour in a sample of 60 criminal offenders in the UK. Most of these men had personality disorders such as psychopathy
• Lea - features of fixed action patterns

  • stereotyped, unchanging
  • ballistic, has to run its course
  • unaffected by learning
  • single purpose
• Gospic - aggression and amygdala 


  P’s were mildly provoked, when reacting aggressively , FMRI scan showed a heightened response by the amygdala. A Benzodiapine drug taken before provocation reduced aggression and reduced the activity of the amygdala.
• Fischer and Greitemeyer - cognitive priming


  Men listened to derogatory song lyric. Acted more aggressively to female confederate and recalled more negative qualities about women in comparison to a control group. Similar results when replicated with women.