image: Colorful patinated “old” flint items recovered from Qesem cave. These items were collected by the cave's inhabitants and brought to the cave from varied landscape localities outside of the cave. Most items were recycled and resharpened in a way that clearly preserves the original outline and patina cover of the original specimen.
Credit: Tel Aviv University
Colorful stones, fossils, and ancient flint tools discovered at prehistoric sites in Israel are at the heart of a new study. The researchers hypothesize that such objects helped people remember places and events from their lives and may have influenced the evolution of autobiographical memory and our sense of self.
Most of us are familiar with the urge to pick up a seashell from the beach or keep a stone from a hiking trip. The object itself may be ordinary, but to the person who keeps it, it serves as a reminder of a particular moment, place, or person. Where did this behavior come from? Did early humans do the same? A new study by Tel Aviv University researchers suggests that this practice stretches back approximately half a million years, with important consequences for the evolution of memory.
The study was led by a team of researchers from Tel Aviv University: Dr. Yoav Ram of the School of Zoology. Wise Faculty of Life Science, Prof. Ran Barkai and Dr. Ella Assaf of the Department of Archaeology, Entin Faculty of Humanities, in collaboration with Prof. Liad Mudrik of the School of Psychological Sciences, Gordon Faculty of Social Sciences, and Dr. Bar Efrati of Oxford University. The study was published in the journal Evolutionary Anthropology.
The study combines archaeological findings with insights from evolutionary theory, psychology and neuroscience. Its authors point to objects that early humans collected, carried, and kept despite having no apparent practical purpose. They propose that these objects may have served as personal keepsakes, reminding their owners of a place they had visited or an experience they had had.
Several examples come from archaeological sites in Israel dating back hundreds of thousands of years. Small, colorful pebbles brought from various locations were found in Qesem Cave, although no practical use for them was identified. In the Sakhnin Valley, researchers discovered handaxes fashioned from pieces of flint containing fossils or unusual geological formations. In some of these tools, these distinctive features were preserved at the center of the stone, where they could be seen and touched. At Revadim, Jaljulia, and Qesem Cave, old flint tools were found that had been collected after their surfaces had changed with the passage of time. Some had been resharpened, but most of their original surfaces and traces of earlier workmanship were preserved. The researchers suggest that the tools’ aged appearance may itself have held value for those who kept them. In a sense, it told the object’s story.
The researchers posit that an object brought back from a particular place could have triggered a memory of a personal experience. Its appearance and texture may also have helped its owner distinguish between an event they had experienced firsthand and a story they had heard from others or imagined.
A keepsake is private and personal; it can be carried from place to place and shown to others. In this way, it may also have strengthened the credibility of a personal account. In human societies, remembering encounters, alliances, gifts, mutual obligations, and rights associated with particular places is highly important. Reliable personal memory can facilitate cooperation, help maintain relationships, and establish trust.
Over many generations, the researchers suggest, the use of keepsakes could increase evolutionary pressures on brain mechanisms responsible for determining the source and reliability of a memory. In this way, material culture and neurobiology influenced one another and contributed to the evolution of autobiographical memory—the ability to organize personal experiences into a continuous life story that underpins our sense of self.
Why might this practice have emerged during this particular period? Prof. Barkai suggests a possible connection to environmental changes: “The disappearance of large animals, particularly elephants, required early humans to develop new hunting methods and become familiar with hunting grounds inhabited by animals such as fallow deer and wild cattle. Objects taken from these places may have helped them maintain a personal connection with the places that would henceforth provide their livelihood.”
The authors emphasize that this is a hypothesis, rather than proof that every unusual stone was a keepsake. Nevertheless, the archaeological record shows that objects associated with memories have accompanied humans from half a million years ago to the present day, making it reasonable to assume that this behavior was likely imbued with meaning and affected human evolution.
Dr. Ram concludes: “When early humans brought a colorful stone or an old tool they had found in the landscape back to their cave, that object may have helped them remember a significant event or encounter for the rest of their lives. In this way, keepsakes may have become a kind of ‘external memory device,’ supporting the evolution of brain mechanisms responsible for autobiographical memory, which is so characteristic of us as humans and so important in shaping our identity.”
Link to the article:
https://onlinelibrary.wiley.com/doi/full/10.1002/evan.70051
Journal
Evolutionary Anthropology Issues News and Reviews