Ancient tools provide clues about early human behaviors

NEW YORK — Stone tools and other items from ancient sites in Kenya give a glimpse at the emergence of some key human behaviors, perhaps including a building of relationships with distant neighbors, new research says.

Scientists can’t be sure whether the objects were made by our species, Homo sapiens, or some close relative that’s now extinct. But at about 320,000 years old, they’re roughly the same age as or a bit older than the earliest known H. sapiens fossils.

In any case, they show “foundations of the origin of modern human behavior,” said Richard Potts of the Smithsonian Institution, one of the researchers reporting the find in three papers released Thursday by the journal Science.

The tools are smaller and more sophisticated than the older, teardrop-shaped stone tools found in the same area in southern Kenya. Some were made of obsidian, which didn’t come from the area, meaning the toolmakers traveled miles to get it.

And those excursions must have led them to encounter groups of H. sapiens. The toolmakers probably made connections with them so they wouldn’t be threatened when they showed up on somebody else’s turf, the researchers said.

The newer tool style, known from other sites as Middle Stone Age technology, produced smaller stone flakes. It required a lot more planning to break off those chips to a desired size and shape, said Alison Brooks, an anthropology professor at George Washington University in Washington, D.C., and another author of the papers.