When we think of violence, we often imagine wars, crime, and brutal conflicts.
But what if human violence isn’t just a result of social structures, politics, or survival pressures?
What if it’s something deeply ingrained in our very biology—something we inherited from our primate ancestors?
A groundbreaking study has taken a step back along our evolutionary tree and uncovered an unsettling truth: humans evolved the tendency to kill each other from our primate predecessors.
Violence, it turns out, didn’t suddenly emerge from civilization or conflict over resources. Instead, it has been a part of us since the very beginning.
And here’s the kicker—when our species first emerged, humans were six times more murderous than the average mammal today.
But before you start thinking we’re the worst of the bunch, guess again. The most violent mammal species on the planet isn’t lions, wolves, or even humans.
It’s meerkats. Yes, the adorable, small, social creatures are far more likely to kill each other than we are.
A Deep Dive into Mammalian Murder
To get to the bottom of human violence, researchers from the Estación Experimental de Zonas Áridas and the University of Granada in Spain analyzed over 4 million deaths across 1,024 mammal species.
Their goal? To determine which species were most prone to intraspecies violence—killing members of their own kind.
The results were eye-opening.
While violence is a rarity in most mammals, certain species exhibit it at shocking rates.
They calculated the proportion of deaths caused by members of the same species and compiled a ranked list of the most murderous mammals.
Surprisingly, humans didn’t even make the top five.
The most violent mammal? Meerkats.
Nearly one in five meerkats—mostly juveniles—are killed by other meerkats. .
It’s an unexpected revelation, considering their playful, cooperative appearance in nature documentaries.
An Evolutionary Legacy
For decades, scientists have debated whether human violence is a product of our culture or something hardwired into our biology.
Some argue that humans became violent due to competition over resources, while others point to our closest relatives—chimpanzees—as proof that violence is embedded in our DNA.
This study found both perspectives to be correct. Lead researcher José María Gómez explains:
“We found that human lethal violence has an evolutionary origin, but it can be modulated by some ecological and cultural factors, like the type of sociopolitical organization.”
To understand how violence evolved in humans, the team examined our ancestral lineage. Typically, species that are closely related display similar levels of violence.
The researchers calculated the expected levels of interspecies murder based on evolutionary history and compared that to real-world data from 600 human populations spanning 50,000 BC to today.
How Murder Rates Have Changed Throughout History
When humans first emerged, about 2% of people (one in 50) were killed by other humans.
But the rates didn’t stay constant—they changed drastically throughout history.
- Paleolithic Era (10,000+ years ago): Lethal violence rose to 3.9%.
- Medieval Period (400-1400 AD): This was the peak of human violence, with 12% of deaths caused by murder.
- Modern Era: Rates of lethal violence have dropped significantly, likely due to organized governments and stricter laws.
Contrary to popular belief, the modern world is not as violent as the past.
The media may paint a grim picture of war and crime, but historical data suggests that humans have actually become less murderous over time.
Can We Become Less Violent?
Not all mammals are violent—only 40% of the 1,024 species studied displayed intraspecies violence.
And while primates were found to be particularly aggressive, human beings have demonstrated a unique ability to curb their violent instincts.
Science writer Ed Yong explains:
“While just 0.3% of mammal deaths are caused by members of the same species, that rate rose to 2.3% in the common ancestor of primates and dropped slightly to 1.8% in the ancestor of great apes.
That’s the lethal legacy that humanity inherited.”
But the most remarkable takeaway? We have the power to change.
Gómez emphasizes that while our past was steeped in violence, our future doesn’t have to be:
“The main message of the study is that no matter how violent or pacific we were at our origin, we can modulate the level of interpersonal violence by changing our social environment. We can build a more peaceful society if we wish.”
Lessons from Meerkats and Mankind
At first glance, it’s shocking to think that human beings inherited their violent tendencies from their primate ancestors.
But even more surprising is the realization that we are not as violent as we once were.
If we take anything from this study, it’s this: violence is not an unchangeable trait.
History shows that humans can evolve beyond our evolutionary baggage, and with continued social development, stricter laws, and cultural shifts, we can continue to create a more peaceful world.
And hey, at least we’re not meerkats.
