Warfare was uncommon among hunter-gatherers, and killings among nomadic groups were often due to competition for women or interpersonal disputes, researchers in Finland have found.
A study in the United States journal Science suggests that the origins of war were not, as some have argued, rooted in roving hunter-gather groups but rather in cultures that held land and livestock and knew how to farm for food.
For clues on what life was like before colonial powers, missionaries and traders entered the scene, anthropologists examined a subset of records from a well-known database that contains information on 186 cultures around the world.
Douglas Fry and Patrik Soderberg, of Abo Akademi University, in Vasa, Finland, chose to examine only the earliest existing records on the people who had no horses and no permanent settlements, leaving them with 21 mobile foraging societies for analysis.
"To be purists, we took only the oldest, high-quality sources for each culture," Mr Fry was quoted as saying in Science, and these studies would best showcase the people's traditional ways.
The groups included the Montagnais people of Canada, the Andamanese people of India, the Botocudos of Brazil and the !Kung people who live in isolated areas of Botswana, Angola and Namibia.
The records contained data on 148 lethal events. Of the 138 killings in which circumstances were "unambigious", 55 per cent were determined to have involved one killer and one victim, the study said.
In 85 per cent of killings, the killer and victim came from the same society. Men were most often the killers. Women were the aggressors just 4 per cent of the time.
"Most incidents of lethal aggression can aptly be called homicides, a few others feud, and only a minority warfare," said the study.
Reasons for the killings varied, with 11.5 per cent stating revenge as the motive, 9.5 per cent saying it was over a particular woman, and 6.1 per cent being cases when a husband killed his wife.
Twenty-two per cent were linked to miscellaneous interpersonal disputes.
Less common motives included fights over resources such as a fruit tree (1.4 per cent).
"In my view, the default for nomadic foragers is non-warring," Mr Fry said.
Some anthropologists, however, said his method of winnowing down the societies for analysis and using only the oldest data on them could have skewed his results.
"The problem with the earliest accounts is they may be sketchy on all sorts of things," said Raymond Hames, a professor of anthropology at the University of Nebraska.
"In my mind, this is a very restrictive way of doing it, which I think accounts for his much lower estimates."
Other researchers have found greater evidence of war-like behaviour among hunter-gatherers.
* Agence France-Presse