How did we become the thinking animals that we are? That’s the question at the heart of the study of human prehistory–and the one that Colin Renfrew has been asking since the summer of 1962, when he travelled to Milos, one of the Cycladic Islands in the Aegean Sea, a source of the black obsidian that was the earliest commodity traded by humans.
Renfrew–Lord Renfrew of Kaimsthorn since he was made a British life peer in 1991 to honor his many contributions to archaeology–was then a graduate student at Cambridge. As an undergraduate, he’d first studied natural sciences before moving on to archaeology; thus, seeking a means to determine the provenance of the obsidian that prehistoric peoples favored for toolmaking, he tried the novel tactic of using optical emission spectroscopy to analyze its trace elements.
“We really hit lucky,” Renfrew told me recently. “Obsidian makes much thinner, sharper blades than flint and so was a preferred substance found at almost all the early Neolithic sites in Greece. In fact, we learned it was already traded during the Upper Paleolithic.” Yet the principal quarries for obsidian in the Aegean were on Milos. “So the material documents the earliest known seafaring,” Renfrew says. “We needed nevertheless to be sure where it was coming from. Trace-element analysis let us characterize each different obsidian source, since they’re created by relatively recent volcanoes and tend to be consistently distinguishable.” Renfrew found that he could clearly graph how far the material had traveled: obsidian from a site in Anatolia (modern Turkey), in one instance, had been transported approximately 500 miles to Palestine. Overall, the picture that emerged suggested a world where most people never traveled more than a few miles from where they were born, but a few went everywhere. “It’s an interesting picture,” Renfrew says. “It was the seafarers who traveled distances, getting around the Aegean Islands quite widely and clearly doing that before the origins of farming.”
Next, Renfrew turned his attention to what had been a cherished assumption in archaeology: that prehistoric cultural innovation originated in the Near East and diffused to Europe. “Just in archaeological terms, I didn’t think that argument was very good,” he says. “In Bulgaria and Romania, I’d been struck by the early metallurgy at some sites. So when radiocarbon dating arrived–particularly when tree-ring calibration came through in the late 1960s–the penny dropped.” The new technological methods proved that, indeed, certain artifacts in Central and Western Europe were older than their supposed Near Eastern forerunners. Renfrew wrote a book, Before Civilization: The Radiocarbon Revolution and Prehistoric Europe (1973), pointing out that “the previous diffusionist chronology collapsed at several points.”
Over the decades, Renfrew has remained at his field’s cutting edge; he was among the earliest advocates of technologies like computer modeling and positron emission tomography (PET), the latter to examine contemporary subjects’ brain activities as they replicated the toolmaking of Lower Paleolithic hominids. In his latest book, Prehistory: The Making of the Human Mind, Renfrew has not only produced a summary of by far the vaster part of human history but also provided an account of archaeology’s advance since European scholars realized some 150 years ago that the human past extended many millennia further back than 4004 b.c.e. (the 17th-century theologian Bishop Ussher’s estimate of when God had created the world). Given its vast subject and its strictures of length, probably the only real criticism one can make of the book is that in its index, under the letter R, the author is missing. It’s a significant omission: Renfrew has informed today’s understanding of human prehistory much as he says Gordon Childe–who is responsible for the concepts of the Neolithic and urban revolutions–shaped thinking during the first half of the 20th century. Like Childe, he has been one of the great archaeological synthesizers, working to construct a theory of global human development. For Renfrew, all archaeology ultimately leads to cognitive archaeology–the branch that investigates the development of human cognition.