Mind, Brain, and Society: The Biology of Violence
New advances in neuroscience and biopsychology can improve our understanding of violent behavior and inform intervention strategies.
Published January 1, 2002
By Fred Moreno, Dan Van Atta, Jill Stolarik, and Jennifer Tang
Academy Contributors

The social sciences have always looked with a wary eye on biological explanations for human behavior. Past reductionist excesses –– like eugenics, radical behaviorism and surgical “cures” for homosexuality or criminality –– have created sensitivity to potentially de-humanizing practices when biology becomes a principal basis for intervention beyond cases of extreme pathology.
Media overstatements, about so-called criminality genes, for example, or the apparent reduced prefrontal cortex size of incarcerated violent felons, often create a backlash against legitimate research in neuroscience and biopsychology.
Yet recent research into biological aspects of stress, anxiety, depression, aggression and substance abuse have yielded extraordinary results, which leaders in the neuroscience community believe will, at the very least, improve our understanding of phenomena such as violent behavior and inform our intervention strategies.
It is in this spirit that The New York Academy of Sciences (the Academy) will use its long experience in organizing neuroscience-related conferences and publications to bring the very best of natural scientific thinking into the domain of societal problems. A “Mind, Brain, and Society” program was initiated this autumn and will be developed over the next several years.
Life Experience and Brain Chemistry
On October 24 at Academy headquarters in New York, Tufts psychologist and neuroscientist Dr. Klaus Miczek, a leader in this research, provided an overview of important findings in violence research, including some based on work with animals in his own lab. Perhaps the most important general insight of recent years has been the recognition that life experience can shape brain chemistry in significant ways, and that experience and neurophysiology form a seamless web. Contrary to the expectation that there would be strong causation from genes, through neurochemistry, to behavior, it turns out that gene expression itself is profoundly influenced by experience.
With respect to violence, this expression occurs in dramatic ways in both aggressor and victim. Miczek’s group found, for example, that defeated animals develop morphine tolerance before ever being exposed to the drug. They observed that during and immediately after a defeat, a mouse feels less pain than before the defeat. Yet days later, the animal actually becomes more sensitive to pain.
While this response has been seen in animals treated with morphine, in this case there was no drug. Just one salient defeat experience can dramatically alter a crucial neurochemical balance, in this case the expression of the c-fos gene and the enhancement of opiate receptors. This same process can lead to hypersensitivity to other drugs, like cocaine. Defeated mice learn to self-administer cocaine at twice the rate of undefeated animals.
Alcohol and Violence
Rats that attack and win also undergo changes. Miczek and colleagues found that a rat with no experience of aggression will have no change in dopamine levels during its winning fight, but that after the fight there’s a drop in serotonin. They then found that the mere anticipation of a fight increased dopamine levels and reduced serotonin levels. According to Miczek, “Salient experiences, defeat experiences, aggressive experiences, single experiences, can result in large, long-lasting and consequential change. Within a few minutes, genetic expression can be set into motion. This can be very important for understanding drug tolerance, sensitization resulting in higher drug taking, preparing for fights, and stress-related diseases.”
Among other things, this kind of research can shed light on the role of alcohol in triggering violence and creating violent individuals. “One of the overwhelming statistics that should impress everybody,” says Miczek, “is the fact that about 60% of all violent acts, whether murders, child abuse, family abuse, assaults, or felonies, are associated with the consumption of alcohol.”
Biological research, when integrated with social-scientific studies, can add to our understanding of how alcohol, drugs, stress, anxiety and life experience influence interactions that involve or lead up to violence.
Miczek is concerned about the current gulf between social science and brain research, but is optimistic that good science can overcome the gap. He also believes that funding for violence research is not nearly sufficient, despite broad recognition that violence is a major public health problem.
Also read: How the Brain Gives Rise to the Mind