Keepsakes May Date Back Half a Million Years, Study Claims

How could keepsakes shape memory?

Here is where the study shifts from archaeology to speculation — informed speculation, but speculation. The paper combines archaeological findings with evolutionary theory, psychology and neuroscience.

The authors propose that an object brought back from a particular place could have triggered memories of personal experiences. Its appearance and texture may have helped owners distinguish events they lived through from stories they merely heard or imagined.

That distinction matters. In human societies, remembering encounters, alliances, gifts, mutual obligations and rights tied to specific places is critical. Reliable personal memory, the researchers argue, facilitates cooperation, maintains relationships and builds trust. A keepsake is private, portable and showable — which may have strengthened the credibility of a personal account.

Over many generations, they suggest, keepsake use could have increased evolutionary pressure on brain mechanisms that determine the source and reliability of a memory. Material culture and neurobiology, in this view, shaped each other and jointly drove the evolution of autobiographical memory — the ability to organize personal experiences into a continuous life story that underpins our sense of self.

Note what is not said: nobody found a label on a pebble saying "souvenir." The whole chain — from stone to memory to brain evolution — is a model, not a measurement.

Why this particular period?

Barkai offers one possible trigger: environmental change. "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," he said.

Again, hedging is warranted. This is a connection to climate and ecology, not a demonstrated cause.

What does this change for the rest of us?

For now, not much in practical terms — but it reframes a familiar question. If the hypothesis holds, the seashell in your pocket is the latest entry in a half-million-year-old practice, one that may have helped build the brain machinery behind personal identity.

The authors themselves stress this is a hypothesis, not proof that every unusual stone was a keepsake. Still, the archaeological record shows memory-laden objects accompanying humans from half a million years ago to today, which makes it reasonable, they write, to assume the behavior carried meaning and affected human evolution.

Ram puts it plainly: "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."

A stone as an external hard drive. The metaphor is appealing. The evidence, so far, is circumstantial — and the authors mostly admit it.