Why we possess an ability and want to kill others has long been asked in the evolutionary circles, but one new study has found it may be down to the primates that we evolved from.

The interesting study conducted by researchers at Spain’s Higher Council for Scientific Research (CSIC), examined thousands of species to assess their rate of murder within their own species. The team led by José María Gómez analyzed humans from 50,000 years ago to now, and nearly 4 million cases of death within 1,024 mammal species to determine murder levels.

It seems humans rate particularly high when it comes to interpersonal violence – almost 2 percent of all deaths looked at were caused by a killing. This is reflected in the Neanderthal and other primates showing we have evolved from a high murderous strain of the evolutionary tree. There is good news, however, as it seems civilization has managed to calm down our killer tendencies with human culture able to control our need for violence which wasn’t shown in other primates such as the chimpanzee.

“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.

Strangely, an unexpected creature topped the most murderous list and it wasn’t the lion, tiger or brown bear – it is the meerkat with almost one in five meerkats being killed by another, the victims usually young.

The study has been seen as the most thorough and creative research into species killing but others are concerned that the rates of murder aren’t as important as the way in which an animal will kill another from its own species.

Details of the study were published in the journal Nature.