Human culture is a fabric woven of stories.
Unlike any other animal we know, we have shifted the majority of our evolution into our culture, it being many orders of magnitude quicker to create and share ideas about new tools and behaviours than it is to evolve a new body shape or instinct.
Our incredible language and social skills, our “…hypertrophic frontal lobes with an exaggerated ability to predict the future” have combined to give us not only the ability to understand long narratives and causal relationships, but also the means to codify and transmit them across generations. Evolution has seized this happy confluence and it’s likely to be the factor that has given humankind the success we now enjoy.
I cannot uncover any research that addresses what I suppose to be the role of grandparents in ensuring the quality of stories handed down. It seems plausible to me that the single-threaded chain of passing a story from generation to generation (parent to child) would allow for rapid incursion of errors, as the memory of the story heard by the parent fades and they redefine “the fuzzy bits” when they retell to the child. Imagine now a grandparent listening to the parent telling the story to the child. They would be able to “quality check” the story and repair any defective parts. This would help to reduce the drift of stories over time. (Genes also have a proofreading function, indicating that it’s a critical part of useful information transfer in biology.)
Australian Aboriginal stories of the dreamtime are thought to date back over 37,000 years. You tell me which of our modern data storage methods will survive as long and still make sense to the reader.
People say we are “hardwired for stories”. I think we are made of stories and we live in stories, and that is our defining characteristic as humans.