Contagious diseases can spread quickly or slowly, depending on a host of factors and the virulence of the pathogenic agent. Virulence is the ability of the pathogenic agent to infect the host and cause the disease. For example, measles spreads quickly, whereas tuberculosis spreads slowly; gang wars and riots spread quickly, whereas other violence spreads much more slowly. For instance, victims of child abuse may become perpetrators of family violence many years later. In addition, on a biological level, as humans built to mimic one another, research involving monkeys have shown that we have certain types of neurons, called mirror neurons that fire when simply watching someone else carry out an action, even when we ourselves are not doing the same thing 16. This transmission of information is controlled by the premotor cortex system, which helps humans learn various behaviors by imitation - including violent behaviors. When we watch someone else behave violently, mirror neurons activate our own motor system as if we are doing the action ourselves 1617. Mirror neurons are suggested to be the missing link in explaining the biological mechanism of how violence spreads like infectious diseases and models the phenomenon of contagion as well defined and seen when one is infected by the flu 16.

Hatred: Where does hatred start? Do we have any role in the shaping of our biology or our neurology or our chemistry, what are the forces and factors that determine our behavior? According to theories of human behaviour, the behaviour of a human being is determined by four primary factors namely, biological factors such as age and sex, biosocial factors which refers to how people interact with each other, cultural factors, specifically the culture which one belongs to, and the situational factors, such as the environmental challenges one faces 1819.

Newton's third law in physics states: that for every action, there is an opposite reaction 2021. Much like Newton’s third law, we speculate that in relation to hatred, once provoked or exposed, an equal and opposing reaction or extreme opposite reaction occurs in response to that action, which manifests as a destructive, contagious disease in the form of hatred, as an emotional or physical response 215. In addition, we need to consider that, although we are wired to respond to other people, there is also a tremendous amount of variability in individuals’ ability to transmit their emotions to others. Some research suggests, more outgoing, and expressive individuals tend to be better transmitters or be more successful at having you feel what they feel 2223.

Contagion appears to involve both biological and social processes. It is pervasive, and yet we are often unaware of the influence of other’s emotions and behaviors on our own. This is particularly striking because the consequences of contagious behavior can be significant’ 23. For example, mechanisms of contagion can occur through a phenomenon known as mass psychogenic illness, in which symptoms are passed from person to person among people who are visible to one another 24. ‘Mass psychogenic illness is an extreme example of the more general phenomenon of contagious behavior: the unconscious transmission of actions or emotions from one individual to another’ 23. Similarly, Hatfield, Cacioppo, & Rapson 22 define primitive emotional contagion as: The tendency to automatically mimic and synchronize facial expressions, vocalizations, postures, and movements with those of another person's and, consequently, to converge emotionally’ (p. 5). Glaeser 25 who analyzes the political economy of hatred, claims that hatred is fostered with stories about the crimes of the out-group (the other side). Yet, these stories are not based on truth. Politicians create hate-fulling stories in order to discredit opponents and create harm-based hatred.

Dr. Martin Luther King, Jr. noted in 1958 that “violence begets violence,” recognizing the contagious aspect of violence. More recently, there is hard science to back up King's observations. Indeed, violence is considered contagious and a public health issue 1726. We see violence causing violence in its most acute setting in cases of retaliations in gang violence 27 and even in war. For example, this was seen in what was called civil, or intrastate, wars, such as following the 2005 bombing of the Samarra Mosque in Iraq, or even what we call wars between states, or interstate wars, such as World War II 26.

Pathological and physical diseases are not the only diseases that are communicable and contagious. Social, mental, emotional processes and behaviors are socially contagious and can spread from one person to another. Some self-destructive teen behaviors, in fact, are extremely socially virulent and can spread among groups as rapidly and destructively as a physically contagious disease. For example, among teens, the results from one study showed that violence can spread up to four degrees of separation 28. Youth violence is a particularly serious problem everywhere, but especially in the U.S. According to David-Ferdon & Simon 29, in the U.S., more youth die from homicide each year than from cancer, heart disease, birth defects, flu and pneumonia, respiratory diseases, stroke, and diabetes combined. Youth homicide rates in the U.S. are three to 40 times higher than rates in similarly high-income countries 2930. In lieu of these findings, it is important to consider the virulent factors that increase the risk of exposure and contagion, such as the contextual aspects, the environment, policies (e.g., gun policies), discrimination, and history that is inherently embedded within the root of our existence.

Given that hatred is a contagious disease and public health issue, then disease is an impairment of the normal state (functionality) of the person or one of its parts that interrupts or modifies the performance of vital functions. Disease is a pathological process, most often physical, sometimes undetermined in origin 31, and it is a disease of the mind 32. Hatred is also a disease of the human heart, soul, and body Hatred is a complex process that attacks humankind and becomes a community disease. In addition, Hatred is a complex state, discrete, involves destructive intent, is contagious to individuals, groups and communities and is often the result of exposure to harm 11415. Abuelaish 15 argues that “A disease is an impairment of an organism caused by external or internal elements that are harmful to that organism and is recognizable by its symptoms. Hatred is a disease. Such a conceptual framework is based on the interplay of exposure, human hosts, and the environment that leads to the production of hatred” 15 ^p.60

Conceptualizing Hatred as a disease requires a valid scientific medical model to investigate the causes, characteristics, and impact of hatred on health and well-being using a multidisciplinary comprehensive and holistic approach rather than a fragmented one. A multisystem approach is needed to include socio-biomedical, psychological, sociological, psychiatric, neurological, and endocrine variables. Hatred is an overlooked epidemic and contagious disease 14.

It is assumed in Engel’s biopsychosocial model that disease or illness outcome is attributed to the intricate blend of biological, psychological, environmental, and social factors described in systems hierarchy from molecules to the universe with the patient at the central interfaces in the hierarchy 33. This model is perceived to be still valuable and important 3435.

The model is also relevant to the concept of hatred as a contagious disease, from a multitude of angles which provides a multidisciplinary approach. Specifically, one which offers a comprehensive, holistic, biomedical model to study the patho-physiology of hatred. This model helps to acknowledge the social, economic, political, environmental, and cultural factors which influence the spread of hatred as a contagious disease, as it is contextual based and depends on who you are and where you are.

Hatred is a public health issue because hatred often engenders violence, sometimes affecting entire populations. Nevertheless, direct, and indirect data suggests that hatred is a public health issue also because of its association (causal, correlated, or otherwise) with several other usually stress-related health problems. Furthermore, hatred itself is disease-like, being caused or triggered by exposure to harmful environmental variables and presenting attributes such as malignancy and contagiousness.

From the literature, it is speculated that the disease of hatred stems from specific or cumulative triggers 36. In our research, we show how hatred is a contagious disease. Using the epidemiological triad (Figure 1), this idea can be further explained 37. This proposed model involves the agent, host, and environment or context. The agent is the necessary factor leading to disease onset (e.g., the harm that can lead to the onset of the disease). The host is the individual or group who is susceptible to the agent. Then the environment is a set of factors that combine with the agent contributing to disease onset. Using hatred in this model, the agent can be identified as a causal trigger or agent to hatred. Examples of the causal agent and triggers include racism, discrimination, violence, hate speech, hate crime, misinformation, fear mongering, bigotry, oppression, and aggression 1415. The host would be individuals who are direct targets of hatred or people who are indirectly exposed to hatred through their environment or media.

We speculate that triggers of specific cases of hatred are likely to be cumulative exposures to repetitive harm, often violent or provocative (physical, psychological, social, political, including deprivation and dehumanization), stimulation. Hatred is interconnected with the triggers as the effect is bidirectional. Hatred causes responses in the person with hatred. These responses include racism, discrimination, violence, etc. Therefore, the response is the same as the initial trigger to hatred, hence, its bidirectionality and interconnected nature 2. However, it is unclear how these triggers lead to hatred instead of other emotional responses, as well as hatred’s means of transmission and its infectivity. There may be a causal relationship between exposure to these triggers and hatred as an outcome, warranting further exploration from a public health perspective 15. Specifically, a public health approach to hatred is needed in investigating its pathophysiology and socio-epidemiology, identifying modifiable risk factors, prevention, and management strategies, and how to predict early detection for early prevention.

Figure 1 presents a model in which Violence/War Related Hatred is associated with a triangular interrelation between the specific characteristics of the individual, the individual experience of harm and the environment in which the individual lives and that has an impact on his emotions. Based on the proposed model, we claim that hatred, while often conceptualized as an extreme form of anger, is an infectious and contagious manmade disease. It is a result of exposure to painful, and deleterious harm attributed to the intricate relationship between contextual, biological, psychological, and social factors and occurs in clusters. We therefore created the five main dimensions of Conflict/War Related Hatred including Group Think, Destructive, Exposure, Chronicity, and Strong Affect (Extreme-Severe). Next, we check their reliability base don the inter-correlations between the variables in each dimension. Finally, we aim to analyze the interrelations between the five dimensions of hatred in order to examine whether they create one unified and valid construct of Conflict/War Related Hatred.

Based on the above theoretical review, the main research questions that are the focus of this paper are: what the dimensions of conflict/war related hatred are; how they are related to each other, and whether they form a combined unified reliable statistical construct. In the Method section below, we present our data collection process in the Gaza Strip, the main demographic variables of the sample, and the five empirical dimensions of our theoretical model. Then we conduct a Second Order Factor Analysis to confirm or disconfirm the interrelations between the five dimensions that lead us to the final Hatred construct that is based on only three reliable and valid dimensions out of the five dimensions in the original model.

The first step was obtaining and ethics approval for the study. Ethics approval from the University of Toronto Research Ethics Board (protocol ID: 37953) was obtained.

The study is cross-sectional and is stratified random sample. The first step was a geographic ratification of the major neighborhoods in the five main cities in the Gaza Strip. Once the five strata were defined, a random sample within each cluster was selected. The data were collected through a community-based face to face survey on the topic of “Developing a Measure of Hatred and its Impact on Health and Wellbeing”, designed and developed by the first author. Then the data were coded, digitized, checked and cleaned by the research team.

Based on the proposed model, we started with a definition of hatred that is based on 122 items (with a 5 points Likert scale), composed by 5 dimensions operationalized as latent constructs: Group Think, Destructive, Exposure, Chronicity and Strong Affect where each of the latent constructs can be measured by specific items and the full model explored and tested as a second order factor model.

1. Contagious/Group Think- One of the components of hatred is group think, defined as an in-group spread of negative ideas about an out-group. Individuals with high level of hatred have a necessity to share their emotional state with others which will give hatred a dynamic similar to that of a traditional contagious disease. 14 items were used to measure this dimension.

2. Destructiveness– Hatred often includes a desire to eliminate /destroy/ control the target of hate physically, psychologically, and/or socially; this often involves a compromise in moral judgement, including self-righteous cruelty and/or lack of remorse. 36 items were used to measure this dimension.

3. Exposure- Hatred often involves distortions in memory, perception, and judgement such as: vulnerability to distorted historical accounts, propaganda, and charismatic leaders; attributions of unrealistic power and importance to the hatred object; evaluation of the objects as bad (dangerous, immoral, inhuman) degrading/devaluing the object as subhuman. 17 items were used to measure this dimension.

4. Chronicity – characteristics are chronic and sometimes obsessive. 16 items were used to measure this dimension.

5. Strong Affect (Extreme-Severe) contains strong, intense affect. 51 items were used to measure this dimension.

Initial descriptive analysis was conducted to evaluate data integrity. Means, standard deviation and proportion of agreement were calculated for each item. Reliability analysis was conducted in SPSS, where Cronbach’s alpha, inter-item correlation, item-total correlation, and Cronbach’s alpha if item was deleted were all calculated and used for a first re-specification of the structure of the 5 constructs. Items were removed if they caused Cronbach’a alpha to increase when removed from the construct and/or if they had a correlation with the total construct score less than 0.30. The total construct score was calculated with the item removed, then a correlation is calculated between this total score and the item. This was done for each and every item in each of the five constructs.

In order to test our theory about the theoretical constructs of hatred, we adjusted a second order factor analysis using software Mplus. The five constructs described above were specified as latent variables following a confirmatory factor analysis structure, where each construct loaded into a single factor: the Hatred Factor. Each of the 5 latent factors were in their turn measured by specific pre-defined observed items that loaded on them. The resulting Second Order Factor model was estimated via full maximum likelihood estimator (FMLE) with robust standard errors 3839. The resulting Second Order Factor model was estimated via full maximum likelihood estimator (FMLE) with robust standard error 3839. The FMLE uses all available data so that subjects with missing values are not dropped out of the data used by the model. The model was evaluated based on fit CFI (Comparative Fit Index), TLI (Tucker-Lewis index), RMSEA (Root Means Square Error of Approximation), SRMR (Standardized Root Mean Square Residual) and BIC (Bayesian Information Criteria) 40, estimated value of standardized loadings and modification indices. The only re-specification of the model was the removal of dimensions that did not load significantly on hatred.

The sample contains 709 subjects that live in the five main cities of the Gaza Strip. The demographic variables of the sample and their distributions are presented in Table 1. The main demographic characteristics are: 47% males and 53% females, the average age was 29.8 with a range of 15 to 71 years. Most respondents were married (48.9%) or single (40.9%) and 50.5% had children. The level of education was relatively high and 47.8% had a university education with a BA degree. For more demographic variables, please see Table 1.

The initial model, as defined by expert input, is shown in Figure 1. Table 2 shows all items in each of the three dimensions and presents the Reliability analysis of each of the five the three final dimensions of Conflict/War Related Hatred

Group Think/Contagious Dimension: Includes 9 items out of the initial 14 items. For all these items, the Cronbach's Alpha if Item Deleted is lower than the final Cronbach’s Alpha that has the value of .73, and therefore these 9 items were included, while the other 5 were excluded.

Destructiveness: Destructiveness is the capacity or tendency to do damage to oneself, other people or beings, or non-living objects. Since harm happens all the time out in the world, I would argue that almost everything in the world contains some element of destructiveness. For example, even a parent’s love for their child, which we might consider the most beautiful thing in the world, becomes destructive when it means lying to the police about a child’s behavior or enabling a child to continue pursuing their drug addiction. People can be exposed to various forms of destructiveness: cultural destructiveness 41, Destructive Leaders 42.

Destructiveness in the context of social pathological disease (Hatred) refers to the capacity of these conditions to cause significant harm to individuals, communities, and societal structures. This harm manifests in various forms, including psychological distress, economic losses, and the breakdown of social order. Social pathologies are characterized by behaviors and conditions that not only deviate from societal norms but also actively deteriorate the well-being of society 43.

Hatred detrimentally affects the health, wellbeing, functionality and social structure of individuals and communities. The exposure to these social pathological agents, unlike medical biological, are rooted in social, economic, and cultural dysfunctions. Therefore, hatred as a contagious disease reflects deeper societal dysfunctions that require comprehensive and collaborative approaches for resolution. Addressing these issues involves economic, educational, and social interventions aimed at creating a more equitable and cohesive society. Understanding the multifaceted nature of this destructiveness is crucial for developing effective interventions and creating a more resilient and cohesive society.

Exposurerefers to the contact or proximity of individuals or populations with factors that can influence health outcomes. These factors can include a subject's attributes (association) or agents (effect), such as biological, chemical, social, ecological, psychological, or physical elements, which may impact their health 44. Exposure encompasses contact over time and space, making it a broad concept that includes short-term (acute), intermediate, or long-term (chronic) contact with these agents.

The effects of exposure are influenced by several factors, including the individual's susceptibility, the virulence and intensity of the agent, and the frequency and duration of contact. Additionally, geographic factors, the time frame, and the nature of exposure (continuous, persistent, cumulative, or intermittent) also play a crucial role. Therefore, measuring exposure involves assessing these elements to understand their potential health effects and identifying how people come into contact with hazardous substances or are exposed to harm 45.

Understanding exposure is crucial in epidemiological research for identifying risk factors, establishing causality, and designing interventions. Further, this concept is integral to understanding the distribution and determinants of health within populations. Accurate assessment and mitigation of exposure are vital for improving public health and reducing disease burden.

Chronicity Dimension: Includes 8 items out of the initial 16 items. For all these items, the Cronbach's Alpha if Item Deleted is lower than the final Cronbach’s Alpha that has the value of.69, and therefore these 9 items were included, while the other 7 were excluded.

Strong Affect (Extreme-Severe) Dimension: Includes 14 items. For all these items, the Cronbach's Alpha if Item Deleted is lower than the final Cronbach’s Alpha that has the value of.73, and therefore these 9 items were included while the other 36 items were excluded.

Our initial second-order factor analysis model had the second-order factor Hatred loading on all the 5 first-order constructs. The model showed reasonable fit indices (RMSEA, SRMR, CFI and TLA were 0.052, 0.075, 0.70 and 0.69 respectively; Chi-square (1415) = 4163, p<0.0001), but the loading of the second-order factor Hatred on the first-order construct Destructive was not significant (loading < 0.001, SE = 0.12, p = 0.979), so that we decided to remove it from the model. Looking at model estimated correlations between the first-order factors, we noticed that Destructive had very low and non-significant correlation (no shared variance) with Group Think and Strong Affect, providing evidence that Destructive is not consistent with the definition of the role of the first-order factors, which are expected to be correlated since they are indicators of the same Hatred construct. The model was then re-specified with the remaining 4 first-order factors and this time we were not able to obtain estimates because of the low shared variance between Exposure and Chronicity, which caused Exposure to also be removed.

Our final model, which loadings of observed items are shown in Table 2, and loadings of the first order factors are shown in Table 3, kept three first-order factor showed improved fit indices (RMSEA = 0.052, SRMR = 0.06, CFI = 0.8 and TLI = 0.78, Chi-square (429) = 1263, p <0.0001).

We argue that this model describes a reasonable hypothesized structure of the constructs involved in the definition of Hatred. As such, Hatred can be measured and quantified by the level of Chronicity, group Think (Contagious) and Strong Affect. The constructs of Exposure and Destructive as defined and operationalized, do not seem fit this Second Order Factor Structure, but could be part of a broader definition of Hatred, one that would include more heterogeneous sub-scales.

Groupthink (contagious): Research could investigate whether exposure to groupthink behaviors and the contagious spread of conformity within a group have any correlations with physiological and psychological health measures. For instance, does being part of a group characterized by groupthink tendencies contribute to increased stress levels, decreased job satisfaction, or higher rates of burnout among individuals?

Chronicity: Exploring the impact of chronicity in group dynamics on health and wellbeing involves understanding how persistent patterns of behavior affect individuals over time. Does chronic exposure to group dynamics marked by conformity lead to feelings of frustration, reduced self-esteem, or even physical health issues? Long-term experiences of chronicity might have cumulative effects on overall wellbeing.

Strong Affect (Extreme-Severe): Investigating the relationship between strong emotional affect and health outcomes is crucial. Does experiencing intense emotions within a group context contribute to mental health challenges, such as anxiety or emotional exhaustion? Are there physiological changes that can be linked to these emotional experiences?

Health Measures and Wellbeing

Health Measures: Further research should explore potential links between the identified constructs and objective health measures, such as blood pressure, heart rate variability, cortisol levels, and immune system function. Are there quantifiable physiological responses that can be associated with chronic exposure to groupthink, strong emotional affect, and other dynamics?

Wellbeing: Research should also delve into the impact of these constructs on overall wellbeing, encompassing psychological, emotional, and even physical aspects. Does being part of a group with chronic groupthink behaviors correlate with lower life satisfaction, a decreased sense of belonging, or even increased rates of absenteeism due to stress-related health issues?

The findings of this research can have implications for organizational policies, leadership strategies, and intervention programs. Understanding how group dynamics affect health and wellbeing can guide efforts to create more supportive and healthy work environments.

The results can also inform the development of targeted interventions that address specific challenges arising from these dynamics. For example, if strong affect is linked to reduced wellbeing, organizations can implement strategies to help individuals manage their emotions effectively.

In summary, further research is needed to comprehensively explore how groupthink, chronicity, and strong emotional affect are related to health measures and overall wellbeing. By understanding these relationships, organizations can make informed decisions to improve group dynamics, enhance employee satisfaction, and foster healthier work environments.

In particular, our research illuminated the following key findings

Group Think (Contagious) Dynamics: We found that the propagation of prejudiced beliefs and discriminatory attitudes within groups tends to be contagious. Individuals often conform to the viewpoints of their peers, leading to an amplification of biased perspectives and fostering an environment conducive to hatred.

Chronicity and Enduring Hatred: Chronic exposure to hatred-inducing content and experiences significantly contributes to the perpetuation of hatred. Over time, these negative influences become deeply ingrained within individuals and groups, making it increasingly challenging to disengage from hateful ideologies.

Strong Affect (Extreme-Severe) Amplification: The presence of strong emotional responses, particularly those categorized as Extreme-Severe, further intensifies the impact of hatred. These emotional states can fuel aggressive actions and encourage individuals to adopt extreme positions, resulting in a dangerous escalation of hostilities.

Considering the implications of these findings, we urge the United Nations to take a proactive stance in addressing the interconnectedness of group think (contagious), chronicity, and strong affect (Extreme-Severe) in the context of combating hatred and fostering global harmony. We propose the establishment of a specialized task force or initiative that concentrates on developing targeted interventions and educational programs aimed at:

Disrupting Group Think Dynamics: Promoting critical thinking and media literacy skills to empower individuals to challenge and resist the contagious spread of prejudiced beliefs within group settings.

Breaking the Cycle of Chronic Hatred: Implementing sustained efforts to counteract chronic exposure to hateful content by promoting diverse and inclusive narratives that encourage understanding and empathy.

Mitigating Extreme Emotional Responses: Designing initiatives to address strong affective responses through emotional intelligence training, conflict resolution strategies, and fostering environments that encourage constructive dialogue.

We believe that by addressing these critical interconnections, we can make significant strides toward building a world that values diversity, promotes understanding, and stands against all forms of hatred. We kindly request your support and advocacy in championing these measures within the United Nations framework.