In a study published this week in the journal Nature, humans were adjudged to be among the most murderous of mammals when “adult V. adult” violence is considered but at the same time we have our evolutionary relatives to blame if needed.

Murderous
Photo by Alexas_Fotos (Pixabay)

New studies show humans as less murderous than cougars

In a new study that poured over existing studies on the veracity and murderous ways of other animals, study lead author Jose Maria Gomez at the University of Granada in Spain points out that humans are, indeed, quite murderous by comparison to other species but that we’ve gotten considerably better since the Middle Ages.

Unfortunately for humans, we’re not on the safest branch on the evolutionary tree nor one known for its pacifism. In fact, we’re on the “wrong side of town” where our mammalian ancestors are concerned.

The study looked at over 1,000 mammal species and found that humans are “in a position within a particularly violent mammalian clade, in which violence seems to have been ancestrally present” but did forgive humans a bit saying we have “inherited their propensity for violence.”

The same 1,000 plus mammal species kill their own at a rate of roughly 3 per 1,000. Our closest relatives in the primate family and in early humans jump to about 20 in 1,000 while the brutality of the years between 700 and 1500 A.D. (medieval times) saw a rise to about 120 per 1000, which is an astounding number.

Based on data from the World Health Organization, Gomez places the human kill rate at roughly 13 in 1000 today and from the aforementioned years that’s significant and shows that “violence has decreased significantly in the contemporary age.”

Somewhat surprisingly given its more common name of the killer whale, orcas have a near zero inter-species kill rate.

Strangely, chinchillas are murderous bastards along with lemurs placing each at over 100 per 1000.

“We found that closely related mammal species tend to have similar levels of violence,” Gomez said. That statement comes through the lens of phylogenetics, the study of evolutionary relationships and the violence of some baboons shows why humans are as violent as the news makes us look.

Others agree with the numbers and value of the study

One of those who spoke about the study and its worth following publication was Harvard psychologist Steven Pinker who authored “The Better Angels of Our Nature.”

“Based on three biological facts — we are apes, we are social and we are territorial — one would predict that humans should engage in lethal violence in our natural conditions,” Pinker wrote in an email. “Modern societies have developed, especially the rule of law, that have reduced rates of lethal violence below what would expect for a mammal with our ancestry and ecology.”

Pinker wrote of the long-term reductions in war, murder, rape and bigotry as the root cause for the reduction of killing by humans since medieval times.

“Our study suggests that the level of lethal violence is reversible and can increase or decrease as a consequence of some ecological, social or cultural factors,” Gomez said building on Pinker’s writing.

Harvard biological anthropologist Richard Wrangham also chimed in with his own praise on the breadth of the recent publication of Gomez’s work but noted that most of the animals that kill more than humans kill infants in the wild unlike day-to-day adult on adult violence that humans seem to “prefer.”

He placed humans among lions and wolves in the “adult-killing club” and perhaps thinking about Chicago’s murder rate this year said that (hopefully tongue-in-cheek ) “humans really are exceptional.”