Published in an international journal, the study shows that mild aggression and lethal violence may have developed through different evolutionary processes. This distinction adds a new perspective to the long-running debate over whether violence is part of human nature.

The research was led by Professor Bonaventura Majoro of the University of Lincoln, along with Dr Samantha Wakes and Professor Marcello Ruta.

Aggression May Not Be a Single Trait

Many theories about the origins of violence treat aggression as one broad behavioral trait. Under this view, species that frequently engage in everyday conflict might also be expected to show higher levels of lethal violence.

However, the new research suggests that assumption may be too simplistic.

The research team examined patterns of aggression across 100 primate species, including humans. Their analysis found that species with higher levels of mild aggression were not necessarily more likely to kill competitors.

Instead, deadly actions—such as killing adult rivals or infants—were distinct from everyday conflicts and appeared to follow their own evolutionary patterns.

Mild Conflict and Lethal Violence Follow Different Evolutionary Paths

The findings cast doubt on the idea that violence can be explained as a single inherited trait.

Rather than shaping behavior across one spectrum—from minor conflicts to deadly attacks—different forms of aggression may emerge under different social and evolutionary pressures.

This suggests that the connection between everyday aggression and extreme violence may be much weaker than earlier theories proposed.

“Understanding the evolutionary roots of violence is important not only for biology but also for the way we think about human behavior,” said Professor of Social Evolution Bonaventura Majoro.

“Our study shows that the evolution of aggression follows a more complex pattern than previous models have proposed, that ranking species based on their general propensity for aggression is biologically inaccurate, and that a more nuanced approach is needed when discussing whether humans are inherently violent.”

What 100 Primate Species Reveal About Aggression

The researchers used a large dataset covering many primate species to compare five different forms of aggression, ranging from routine conflict to lethal attacks.

They found that different types of lethal aggression were moderately related to one another. However, these forms of deadly violence had little association with mild aggression.

This pattern suggests that the biological and evolutionary mechanisms behind lethal violence differ from those that drive everyday conflict.

The findings contribute new evidence to a long-standing debate in anthropology and evolutionary biology about what shapes human violence. Researchers have long examined whether violent behavior is primarily rooted in deep evolutionary history or is more strongly influenced by social and cultural forces.