Our Modern Epidemic
Publish Date: April 17, 2026
Author: Dr. Jeffrey A. Lieberman
Source: Shrink Speak substack
Personal Deviant Violence: Why Mass Shootings and Family Killings Are Preventable
(Dr. Jeffrey Lieberman explains Personal Deviant Violence – the mass shootings and family killings that are foreseeable, identifiable, and preventable)
The modern world has a violence crisis – and now, that crisis has a name. Listen to the full lecture to learn about Personal Deviant Violence, or read through the transcript below.
[ In the audio episode, Dr. Lieberman explores the phenomenon of Personal Deviant Violence – a troubling form of violence that persists even as society becomes safer overall ]
A Decline in Lethal Human Violence
The history of humankind has been impressive in all respects, including first and foremost the one that I'm involved with as a physician – advances in medical science. And civilization has progressed in a way that has made things better for people: given them a better quality of life, extended life expectancy, and also kept them safe and protected. In other words, the likelihood in the modern age of somebody having their life foreshortened by lethal violence from war, crime, assault, and robbery is less than ever in human history.
Believe it or not, this is the safest time in human history to be living – knowing that your life may end because of an accident or a disease, not because of some lethal form of violence.
Now, violence is the manifestation of an inherent drive in human beings: aggression. Aggression was adaptive, at least in ancient times, because we needed shelter, we needed food, we had to protect our families. But over the advances of civilization, with laws, with ethics, with government, with law enforcement, with better living conditions, we've sublimated this aggression into adaptive forms like competition in sports, achievement through professional activities, discovery through science and engineering, and all kinds of other things that provide new technology.
That adaption has kept us safer than before. And if you need proof, you can look at the data – since ancient times to the present, the likelihood of somebody's life ending from lethal violence is lower than ever before.
The only time that it has shown a rise has been in the 20th century with World War I and World War II. So this is really another manifestation of the advances of civilization and how they have been salutary for humankind.
There's one exception, however – and that's something called Personal Deviant Violence.
Personal Deviant Violence is a term that my colleagues and I are using to encompass specific forms of violent behavior that are lethal.
Types of Personal Deviant Violence
The main type of personal deviant violence that we’re hearing about now is called personal mass violence – defined by law enforcement agencies such as the FBI as a single perpetrator, more than three victims, a motive that is mysterious or unknown, and the victims generally being either strangers or people that don't have a clear connection to the perpetrator.
In addition to mass violence, the other types of personal deviant violence that we talk about are:
Intra-family violence, such as parricide, as in the tragedy with Rob Reiner and his wife from their son Nick; or infanticide, such as occurred tragically with Andrea Yates, the woman in Texas who drowned her five children under the influence of her psychotic symptoms.
There's political violence, of which President Trump has been a victim in his term.
There's a form of severe stalking that can occur.
And then probably the most notorious of all is serial killing – as exemplified by David Berkowitz, the .44 caliber killer, Son of Sam; the Zodiac Killer; the Boston Strangler; and Jeffrey Dahmer, the cannibal. These are instances which occur much less frequently now. They peaked in the late 80s and 90s, and our culture is given the credit for why this is happening less than before. Because thinking back to the 80s, this is the era of political strife in the aftermath of the counterculture, which also produced people like Charles Manson. So these have subsided, but in their place, personal mass violence and familicide have risen dramatically.
And even though the overall arc of lethal violence has decreased, these types of violence are being stimulated by our culture and by the degrees of freedoms that are given to people. And then in the United States, they’re amplified in their lethality by the ready access to firearms, including assault weapons.
Personal Deviant Violence is the one form of violence that has eluded the civilizing effect that has occurred in our society over the various millennia that humankind has existed.
Now when these things occur, there's tremendous penetration of the media and reaction by the public of, "This is horrid. How could this possibly happen? We don't get it. This has got to stop." But after that, people move on with the 24-7 news cycle, and they regard these as kind of unpredictable, non-understandable acts of fate or freaks of nature – like you're driving down a road and your car goes over some stones and one of the pebbles is propelled by the tires into the windshield and your windshield cracks – something you couldn't avoid. Or you're on a golf course and a thunderstorm begins and there's a lightning strike.
Pamela Tilton, right, comforts Che James-Riley, 18, as they light a candle at a memorial for the victims of the shooting
at Marjory Stoneman Douglas High School, Feb. 15, 2018, in Parkland, Florida.
But these are not acts of nature; they are not unpredictable, they are not unforeseeable, and they are not unpreventable. These forms of violence are the ones that have eluded the civilizing effect that has occurred in our society over the various millennia that humankind has existed. These are understandable, foreseeable, the individuals who are vulnerable to them are identifiable – and therefore they are preventable.
But instead, we're turning into a gulag. We're turning into a correctional system where we have metal detectors in every building we enter, or we have searches of our bags. We're not looking at the reasons for this violence and how it can be stopped. We're simply listening to the grisly stories to titillate us. And that is the fault of the media – they tell the story and entertain but without informing the public.
And so we're calling on media and the government to pay attention to the fact that these instances are increasing dramatically. In fact, the Gun Violence Archive counted more than 400 mass shootings in 2025 – defined as any incident in which four or more people are shot. That's more than one a day.
This is inconceivable and intolerable. And if there were nothing that we could do because this is simply like global warming or some other type of inexorable process that is so complicated we haven't been able to figure out a solution to it, then so be it.
But it's not.
And as psychiatrists, we're calling upon the institutions of society that are positioned to influence the factors which are stimulating these behaviors to think about this – and to take steps to try and eliminate these causal or accelerant factors.