Six to 10 percent of early humans were preyed upon by predators, claim anthropologists, countering earlier belief that our ancestors were hunters with a killer instinct.

Anthropologists at Washington University who have revealed this theory in their book "Man the Hunted: Primates, Predators and Human Evolution", said people who were preyed upon were short, peaceful and mostly fruit eating, reported the online edition of Discovery Channel.

"Our ancestors from around seven million years ago until around 500,000-60,000 years ago huddled together defensively in groups to avoid becoming some predatory beasts' dinner," the authors Donna Hart and Robert Sussman said.

"Even the invention of stone tools approximately 2.3 million years ago did not alter the playing field much. These were not hunting tools or weapons for use against large mammals."

"Think of walking up to a mammoth or even a large deer and hitting it over the head with a small stone. These were not tools which one could approach a large mammal close enough to be successful in hunting and killing it," the researchers said.

According to them most early humans either did not hunt at all or killed only insects or "things like small rabbits and birds (that were) taken opportunistically."