In the Indonesian island village of Langda, located on Irian Jaya near its border with Papua New Guinea, a half-dozen men sit in an open space, chipping fragments out of rocks. It's not rocket science, but it's a veritable rock science still practiced by a handful of groups around the world. The men are making double-edged stone blades for adzes, scythe-like tools with wooden handles that the Langda have traditionally used to clear land and to work wood. Several of the men show great dexterity in shaping stones into implements, a process known as stone or flint knapping. Each man holds a grapefruit-size stone in his right hand that he uses as a hammer to strike a rock braced against a piece of driftwood with his left band.
Deitrich Stout, an anthropology graduate student at Indiana University in Bloomington, sits among the men. To him, the situation is the next best thing to traveling back in time to witness what otherwise would be a lost art.
The men's work is going well. One craftsman proclaims his joy by crying out the name of a mythical figure revered as the provider of adze-worthy stone. A second man smiles and describes the stone strips, or flakes, that he's pounding from a blade as "peeling off like sweet potato skin." A third experienced adze maker talks excitedly of wanting to slice flakes off "every stone in the river."
Their duties encompass more than knapping stones. The skilled workers pause periodically to monitor and advise apprentices gamely pounding at their own potential blades. "Work more slowly," they might say. Or they might offer advice on proper knapping technique and posture or outline strategies for shaping a particular stone.
To Stout, the opportunity to observe interactions between the master stone workers of Langda and their apprentices may help him and other scientists recognize the handiwork of experts and apprentices on stone artifacts dating back thousands and perhaps even millions of years. And it could provide a window on the way ancient technological skills passed from generation to generation.
"Stone tools provide hard evidence of skilled performance that will be invaluable for determining when and how the social learning of tool making emerged," Stout says.
His research, published in the December 2002 Current Anthropology, appears at a time of ferment in investigations of both ancient and modern toolmakers. Some archaeologists now see a surprising amount of technical aptitude and regional variability in the earliest known examples of stone-tool fabrication and use. These observations challenge the traditional notion that knapping practices evolved slowly and uniformly, steadily increasing in complexity as time passed.
What's more, psychologists who study how children develop motor abilities (SN: 3/20/99,p. 184) have been weighing in on ancient tool use. They're finding that toddlers learn to use toy tools on their own by exploiting well-practiced hand and arm actions from infancy combined with the added freedom of hand movement that comes with standing upright. If 1-year-olds can walk their way toward simple types of tool use, then founding members of the human evolutionary family--who adopted a two-legged stride perhaps 8 million years ago--could have done so as well, these researchers suggest.
ROCK ON In the fall of 1999, a group of five expert and five apprentice Langda adze makers welcomed Stout into their fold. They were flattered that an outsider wanted to observe a craft that they regard with great pride.
The process begins with a trek down a steep valley to a river, where seasoned workers select promising boulders. They strike small chunks from the best candidates to look for a uniform grain under the surface and other signs of internal strength. When they uncover the best boulders, the stone workers crack them open using a set of hammering stones, sometimes also relying on the heat of a fire to weaken the boulders. …