The Neuroscience of Aggression: Why Humans are Drawn to Violence

A detailed analysis of aggressive behavior in our modern world, in conjunction with an examination of human history, reveals that our species has a significant, deeply complex connection with violence. Every year, approximately 1.6 million people across the world die because of violent behavior and conflicts, and many more are injured or gravely affected [1]. Even beyond real life violence, humans are drawn to the violent and hostile images, movies, and video games that have become pervasive in modern culture.

Recent developments in neuroscience indicate that specific parts of the brain and concentrations of brain chemicals may affect a person’s propensity towards violence. Additionally, new studies in the fields of genetics, neuroscience, and biochemistry are evaluating reasons for human attraction to violence in entertainment and society. These studies suggest that the traditional legal and policy approaches to combating violence must be re-evaluated and replaced with a legal framework that considers the ethical and neurological implications of violent behavior.


A Neurological Basis

Brain chemistry plays a major role in determining the likelihood that a person will lash out in a violent manner. Specifically, studies implicate chemical imbalances and anomalies in neural structures as potential indicators of aggressive behavior. One of these relevant regions of the brain is the pre-frontal cortex, which controls behavior, personality, decision-making, and social behavior.

Adrian Raine, from the University of Pennsylvania, discovered through a brain-imaging study that antisocial and aggressive individuals are more likely to have experienced or are born with brain damage in the prefrontal cortex, as well as the amygdala and the angular gyrus [2]. Further research on violent behavior in teenage boys suggests that increased neuronal activity in the amygdala, which processes fear and emotions, is correlated with more aggressive behavior. Similarly, diminished activity in the frontal lobe, which is associated with decision-making, may promote violent actions. Abnormal levels of specific neurotransmitters and hormones that fluctuate in response to stress, such as dopamine and serotonin, are also related to aggressive behavior [2].

However, internal neurological factors are not the only determining factor in aggressive behavior: societal pressures, such as constant stress and anxiety, often reinforce the violence present in today’s world. Stressful social situations are connected to increasing mental illnesses such as depression and even immune-related illnesses.

Psychoanalysts study these phenomena through evolutionary psychology, which attempts to explain social behavior as a product of evolutionary and physical attributes [3]. Although the field certainly lacks consensus, many evolutionary psychologists suggest that aggression is an evolutionary adaptation designed for survival [4]. Evolutionary processes have imprinted within the human brain a certain affinity to aggression and violent behavior. In ancient times, our ancestors behaved violently as a necessary response for survival in the dangerous world [4]. But in more recent history, humans have resorted to violent activity to resolve disputes, indicating the remains of our violent tendencies.

Violence in the Media

Popular media often reinforces those tendencies. Violent movies and video games attract large numbers of fans, quite possibly because humans are instinctively attracted to the thrill and suspense associated with portrayed violence. Findings by the University of Augsburg and University of Wisconsin-Madison suggest that violence attracts movie-watchers because it offers insights into human behavior and real-life situations [5]. Violence also provides a mechanism for experiencing ideas, such as the triumph of good over evil, which provides a rewarding experience that often becomes a truth-seeking mission [6,7].

Despite these findings, studies regarding the human attraction to violent entertainment are inconclusive, suggesting widely varying motives for human fascination with aggression. Additionally, research cannot definitively declare that violent entertainment produces real-life aggression, but the thriving presence of such lucrative forms of entertainment suggests that humans are not only naturally attracted to but also enjoy violent behavior.

Treatment of the Mentally Ill

The prevalence of studies connecting neurological factors to violent behavior presents ethical and social challenges to today’s world. Unfortunately, our society has attached and maintained a significant social stigma to mental illness and its related concerns; recent research may exacerbate this problem and further ostracize those with neurological diseases. Policymakers and the media often perpetuate this portrayal of mental illness, representing mentally ill patients as threats to the well-being and stability of society. Such representations are rooted in a belief that in order to prevent violence, society should remove those who present potential threats.

Movies, television shows, and even common news sources re-entrench the belief that mentally ill patients should be shunned [8]. Unfortunately, these dangerous representations greatly skew public perception of mental illness, as people mostly rely on these sources for information [9]. Research suggests that media representations often overpower personal experience when applied to mental illness, because people assume those in the spotlight are qualified and make comments based on facts [9]. Instead of making inflammatory remarks, policymakers and journalists should instead espouse solutions oriented around handling mental illnesses, and they should portray the many positive contributions of such individuals.

These representations also instill a belief that violence is inevitable, forcing people to accept that violence is a central aspect of the human condition. According to a report by the World Health Organization, violence is perceived as an “inevitable part of the human condition” because of its widespread prevalence in society [1]. However, the report suggests that widespread public campaigns can alter these pessimistic perceptions and counter growing aggression. Further public health programs and campaigns (as suggested below) may present a positive solution to violence in society.

Implications for Law and Policy

Studies connecting brain damage with violence or antisocial behavior present significant ethical challenges to the status quo legal framework for defeating violence and crime. According to Adrian Raine, violent criminals cannot be held accountable for their actions if brain injuries impair their moral decision-making [2]. This belief raises the question of what kind of punishment violent, mentally ill criminals deserve. Currently, jails and prisons serve as mental institutions, and mentally ill patients are significantly more likely to be imprisoned through the courses of their lives [10]. However, this legal model fails to resolve the real issues behind both mental illness and violence. As prisons overflow, the judicial system overall becomes less effective.

Additionally, policy proposals that report mentally ill patients to the authorities before they commit crimes are both ineffective and discriminatory. For example, New York state has implemented a statute that requires authorities to report any patients who have the potential to inflict harm on anyone else [11]. These laws are ineffective and insufficient because they address neither the root cause of the problem nor related to mental illness [11]. More importantly, these laws are unfair because most patients do not truly pose a threat to society, and mentally ill patients are 11 times more likely to be the victims of a violent incident [11].

Rather, policies should emphasize treatment and prevention; all levels of government should adopt public health campaigns to encourage more effective programs for at risk patients rather than setting dangerous precedents with discriminatory laws. These public health policies offer more effective solutions than legal restrictions and crackdowns, as proven by other public campaigns like those against tobacco and alcohol usage [1]. Humankind has reached its evolutionary supremacy because of a fine balance between aggressive and compassionate tendencies. Unlike most other species, human beings, in addition to being intellectually advanced, are capable of evincing sympathy and avoiding impulsive behavior. In order to continue thriving, society needs to maintain this careful equilibrium between violence and peace by responding to new research on the causes of belligerent behavior.


[1] Krug, Etienne G. World Report on Violence and Health. Geneva: World Health Organization, 2002.

[2] Society For Neuroscience. “Brain Chemicals Involved in Aggression Identified: May Lead to New Treatments.” ScienceDaily. Last modified November 7, 2007. Accessed December 2, 2013.

[3] Buss, David M., and Todd K. Shackelford. “Human Aggression in Evolutionary Psychological Perspective.” Clinical Psychological Review 17, no. 6 (1997): 605-19. Accessed December 2, 2013.

[4] Elbert, Thomas, R. Weierstall, and M. Schauer. Fascination Violence: On Mind and Brain of Man Hunters. N.p.: National Institutes of Health, 2010.

[5] International Communication Association. “What Attracts People to Violent Movies?” ScienceDaily. Last modified March 28, 2013. Accessed December 2, 2013.

[6] Wood, Janice. “Why Do People Like Violent Movies?” Edited by John M. Grohol. Psych Central. Last modified March 30, 2013.

[7] Goldstein, Jeffrey. “The Attractions of Violent Entertainment.” Media Psychology, 1999, 271-82. Accessed December 2, 2013.

[8] Tartakovsky, Margarita. “The Media and Mental Illness: The Good, the Bad and the Ridiculous.” PsychCentral. Last modified 2011. Accessed December 2, 2013.

[9] Alexander, Taylor. “Stigma Matters: The Media’s Impact on Public Perceptions of Mental Illness.” Ottawa Life, February 2009, 31-33. Accessed December 2, 2013.

[10] “A Guide to Mental Illness and the Criminal Justice System.” National Alliance on Mental Illnesses. Accessed December 2, 2013.

[11] Goode, Erica, and Jack Healy. “Focus on Mental Health Laws to Curb Violence Is Unfair, Some Say.” New York Times, February 1, 2013, New York edition, A13. Accessed December 2, 2013.

Image Credit:

[1] Retrieved February 25, 2014 from: Wikimedia Commons. Labeled for reuse.


Ayush Midha is a student at the Harker School. Follow The Triple Helix Online on Twitter and join us on Facebook.