Beyond deaths and injuries, highly prevalent forms of violence (such as child maltreatment and intimate partner violence) have serious lifelong non-injury health consequences. Victims may engage in high-risk behaviours such as alcohol and substance misuse, smoking, and unsafe sex, which in turn can contribute to cardiovascular disorders, cancers, depression, diabetes and HIV/AIDS, resulting in premature death[16] In countries with high levels of violence, economic growth can be slowed down, personal and collective security eroded, and social development impeded. Families edging out of poverty and investing in schooling their sons and daughters can be ruined through the violent death or severe disability of the main breadwinner. Communities can be caught in poverty traps where pervasive violence and deprivation form a vicious circle that stifles economic growth. For societies, meeting the direct costs of health, criminal justice, and social welfare responses to violence diverts many billions of dollars from more constructive societal spending. The much larger indirect costs of violence due to lost productivity and lost investment in education work together to slow economic development, increase socioeconomic inequality, and erode human and social capital.

Violence cannot be attributed to a single factor. Its causes are complex and occur at different levels. To represent this complexity, the ecological, or Social ecological model is often used. The following four-level version of the ecological is often used in the study of violence: The first level identifies biological and personal factors that influence how individuals behave and increase their likelihood of becoming a victim or perpetrator of violence: demographic characteristics (age, education, income), genetics, brain lesions, personality disorders, substance abuse, and a history of experiencing, witnessing, or engaging in violent behaviour.[17][18] The second level focuses on close relationships, such as those with family and friends. In youth violence, for example, having friends who engage in or encourage violence can increase a young person’s risk of being a victim or perpetrator of violence.31,32 For intimate partner violence, a consistent marker at this level of the model is marital conflict or discord in the relationship. In elder abuse, important factors are stress due to the nature of the past relationship between the abused person and the care giver. The third level explores the community context—i.e., schools, workplaces, and neighbourhoods. Risk at this level may be affected by factors such as the existence of a local drug trade, the absence of social networks, and concentrated poverty. All these factors have been shown to be important in several types of violence. Finally, the fourth level looks at the broad societal factors that help to create a climate in which violence is encouraged or inhibited: the responsiveness of the criminal justice system, social and cultural norms regarding gender roles or parent-child relationships, income inequality, the strength of the social welfare system, the social acceptability of violence, the availability of firearms, the exposure to violence in mass media, and political instability.