The san hunter-gatherers of southern Africa establish social networks by exchanging gifts, often glass or ostrich-eggshell beads, strung into a necklace or sewn onto a bag or hat. The gifts help secure future favors, says anthropologist Stanley Ambrose of the University of Illinois in Urbana-Champaign. As one San man told a researcher to whom he gave a gift, "It's free! It's yours! And don't you forget it!" According to Ambrose, such gift giving may have been established more than 40,000 years ago. He has found ostrich-eggshell beads of that age in Kenya, which rank among the world's oldest ornaments and may have given early humans in Africa an edge over their competitors.
Ambrose has been working at a rock shelter called Enkapune Ya Muto, or Twilight Cave, in Kenya's Rift Valley. There, among thousands of stone tools, he discovered the remains of an ostrich-eggshell bead workshop. He found nearly 600 shell fragments, as well as 13 complete beads. The finished beads have a hole drilled in the middle.
According to Ambrose, early Africans may have used beads the way the San do now, as a social survival mechanism in a difficult environment. Though the climate in East Africa was generally cooler and drier 40,000 years ago than it is now, the period was also marked by dramatic fluctuations in climate. Social ties, established by gift giving, would have helped people in tough times. "If there's a drought and you have to move, the place you're most likely not to get turned away from is the place where you have stored obligations and relationships," says Ambrose. "It's the original social security system."
Support from neighbors would have helped early humans survive while others failed. "It gave the African people an advantage over Neanderthals, who may not have had a symbolic mechanism for social solidarity," says Ambrose. "The bottom line is, in competition between species in an unpredictable environment, the gift is mightier than the spear."