Stone Age signs of complexity

A pair of 77,000-year-old pieces of engraved ochre found in a South African cave lend credence to the view that symbolic forms of thinking, considered crucial for modern human behavior, emerged surprisingly early in the Stone Age.

An ancient piece of engraved ochre found in South Africa features a geometric design. Science

An international research team led by Christopher S. Henshilwood of the South African Museum in Cape Town unearthed the artifacts in the Blombos Cave near the country’s southern tip. Both chunks of ochre have surfaces that were ground smooth before cross-hatched designs were etched into them, the researchers report in a forthcoming issue of Science.

The scientists determined the engraved objects’ age by analyzing radioactive isotopes in charred bits of stone from the layer of soil in which the artifacts were unearthed.


Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.