The 5-step social identity model of the development of collective hate is a theoretical framework that is used to explain why in-group discrimination against and out-group develops and how this can lead to acts of violence and extreme prejudice. ^[1] On the basis of social identity theory, Stephen Reicher, Alexander Haslam, and Rakshi Rath established the model in their foundational paperMaking a Virtue of Evil: A Five-Step Social Identity Model of the Development of Collective Hate' (2008) ^[1] The model was created to outline the cognitive processes that must occur for an individual to justify and carry out acts of evil.

Social identity theory underpins this model by introducing the role of self-conception in intergroup behaviour. ^[2] It describes in-group behaviour as the product of social influence, individuals develop a sense of belonging to a group due to shared goals and values. ^[3] An out-group develops when another group of people are perceived as 'others', their differences from the in-group are exaggerated and stereotyping develops, often fuelled by a leader. ^[4]

The first step is Identification in which individuals create a cohesive in-group with others who share their goals and values, this gives the individual a sense of belonging making the group integral to their self-concept.

Exclusion of the out-group is the second stage, distinctions between the two groups are overstated which leads to discrimination. Differentiation from the out-group occurs due to psychological benefits of group membership, such as social support networks and increased self-esteem. ^[5]

The third element of the model is the Threat which the out-group poses to the in-group identity. In-group leaders use propaganda to convince other members that the out-group pose as a threat to the in-groups goals and values, this fuels the mistrust of the outgroup.^[5]

Step four has been coined Virtue as the in-group is represented as uniquely good, in comparison to the out-group which is dehumanised making violence against them justifiable (to some group members).

Finally, Celebration occurs when the in-group becomes morally disengaged, which allows organised violence against the out-group to be deemed as rational in order to protect group values. ^[1] Inhumane acts against others are often a source of pride for the in-group members. The progression of collective hate development, using the 5-step model, has been reflected in past historical genocides.

Nazism has been used by Reicher and Haslam as a case study for the 5-step model. The framework is not exclusively based on the Nazi Regime but draws examples from it to exemplify how simple in-group formation can escalate to inhumane violence against an out-group. Adolf Hitler's ideology was to seize power throughout 1930's Germany by forming an 'Aryan race' and persecuting any individual who didn't align with his views (specifically Jew's). ^[6] In doing so, Hitler was able to identify a clear in-group that was central to his agenda. The exclusion stage occurred through the marginalisation of Jewish, Romani and disabled people forming an out-group. Nazi's utilised propaganda and shared values to unite the 'Aryan' people, and exaggerate the distinction between themselves and the 'inferior' out-group. ^[7] Nazi propaganda was used to portray Jews and other minority groups as threats to the 'Aryan' values. For example, Jewish people were wrongly accused of spreading 'atrocity stories' to enemy lines during World War II.^[8] The Nazi regime portrayed the 'Aryan Race' as virtuous by justifying their immoral actions as necessary to protect the superior German values. Positioning Nazism as morally superior allowed the out-group to be dehumanised which warranted violence against them. ^[1] As more of the population became converted to the Nazi regime, the in-group became further morally disengaged from their behaviour. Acts of violence against the out-group became something to celebrate, and were seen as necessary to protect the future progression of the movement, according to in-group members. ^[9]

Hannah Arendt's term Banality of Evil' was first coined in her book 'Eichmann in Jerusalem' (1963)^[11] and inspired for the 5-step model of collective hate. She claimed that acts of evil become banal when ordinary people participate unthinkingly.^[11] The concept is mentioned frequently in Reicher, Haslam, and Rath's article 'Making a Virtue of Evil: A Five-Step Social Identity Model of the Development of Collective Hate' (2008).^[1] Both theories share central themes, such as focusing on what makes ordinary individuals commit inhumane acts of violence. ^[12] Arendt's idea stemmed from viewing Adolf Eichmann's trial in Jerusalem, for his role in mass murder as an organiser of the Holocaust.^[13] She claimed that Eichmann appeared to be a typical, ordinary man which did not align with his psychiatric assessment of ‘a man obsessed with a dangerous and insatiable urge to kill’.^[11] This led Arendt to challenge the idea that evil people are a distinct breed, but rather suggesting that any individual can commit acts of mass murder given the correct circumstances.^[12] The first condition is the presence of an Authoritarian structure, in which individuals act under the orders of an established leader. This increases the chance of a person falling into the agentic state where they unthinkingly act as an agent for an authority figure's instructions without feeling any moral responsibility for their behaviour, such as Eichmann obeying the Nazi dictatorship principle of Führerprinzip. ^[12] Arendt also suggested that totalitarian regimes aim to instil fear throughout society to cause conformity, ^[14] a process by which individuals adopted the Nazi values in an act of self-preservation.

One major criticism of the 5-step model is the focus on social identity over biological factors. The foundational paper claims that collective hate develops due to specific group dynamics, as individuals are not born evil but influenced by their environment to act in a malicious way. ^[15] However, it's been argued that this approach largely overlooks innate dispositions for evil. In other research, the majority of good and evil is attributed to genetics,^[16] as personality correlates in antisocial behaviour have been found to be heritable.^[17] Twin studies have revealed strong genetic heritability for antisocial traits such as impulsivity (a tendency to act quickly without thinking)^[18] implying that genetics may play a large role in controlling manifestations of conduct disorders that involve impulse control.^[16] This research suggests that genetic factors may influence a person's tendency to conform to violent groups, but the 5-step social identity model of collective hate doesn't address this.

The model has also been criticised for creating complications in assessing blame for collective hate crimes. Arendt's idea of an Authoritarian structure makes it difficult to apply legal accountability to individuals if they are able to claim they were acting in the agentic state.^[12] For example, some psychologists have argued that Eichmann was obeying the Nazi dictatorship principle of Führerprinzip ^[12] when ordering mass murder. This could absolve him of accountability for his crimes^[11] by stating he was not acting on his own accord. Critics argue that this concept creates issues when attributing responsibility for group crime to individuals.

Critics argue that the 5-step model is supported by past research. Stanley Milgram and Phillip Zimbardo were the first psychologists to focus on the importance of group context in behaviour, transforming post-war social research.^[1] Milgram admitted to drawing inspiration from Arendt's Banality of Evil;^[11] claiming that through his obedience experiments he found that when faced with strong authority, people transfer control to the experimenter and only focus on how well they can fulfil orders. ^[20] Psychologists claim that the findings of Milgram's research show that 'everyday' Americans are capable of inhumane acts of cruelty, through thoughtless conformity to authority.^[1]

Zimbardo's Stanford Prison Experiment exemplified these findings, participants assigned the role of 'guard' conformed blindly as a natural consequence of wearing a uniform that created a perceived sense of power. ^[21] Zimbardo claimed that in institutional settings people lose the ability to question authority or make informed moral choices, it's the social setting and system which leads to evil behaviour and not the individual's disposition.^[22]

The events occurring in Abu Ghraib prison (2003-2004) have been compared to the processes of collective hate. During the Iraq war, American soldiers formed a distinct in-group against Iraqi detainees, who were reportedly referred to as 'terrorists'.^[22] Prisoners were dehumanised through various forms of torture (being denied clothing, raped, attacked) which some researchers argue stripped them of their personal identity, making it easier for soldiers to commit inhumane acts. ^[24] Reports imply that guards were taught to see the detainees as a threat, making the torture they carried out appear necessary to protect the American Army. The abusive behaviour was normalised in the prison and in-group members reported it as a source of pride and entertainment .^[25]

Some researchers argue that the model helps predict and prevent collective hate.^[26] In the past, leaders have been able to diffuse group conflict by uniting in-groups and out-groups, encouraging cooperation. For example, American Isolationism (1930's) advocated for non-involvemnet in European and Asian conflicts by promoting policies that call for non-entanglement in foreign war.^[27]