What makes human culture—our shared knowledge passed down through generations—more potent than the cultures found in animals?
The question “What sets our species apart?” has puzzled scientists for centuries. Now, a researcher from Arizona State University has introduced a new theory that may alter our self-perception and understanding of the world.
According to evolutionary anthropologist Thomas Morgan, in a recent paper published in Nature Human Behavior, “A decade ago, it was largely believed that our ability to accumulate and evolve culture was what made us unique. However, new insights into animal behavior are challenging this notion and prompting us to rethink what distinguishes our cultures, and us as a species.”
Morgan works as a research scientist at the Institute of Human Origins and is also an associate professor at the School of Human Evolution and Social Change.
Much like how humans transfer knowledge to their offspring, when a new queen leafcutter ant emerges, she brings along a small piece of her mother’s fungus to establish a new colony. This practice has been in place for millions of years, leading to the fungus in these colonies becoming genetically distinct from the wild fungus surrounding them.
Research indicates that, similar to the evolution of human languages, the songs of humpback whales also change over time, spreading among groups and becoming more intricate. Additionally, chimpanzees demonstrate the ability to learn tool use, with evidence showing they have been doing so for thousands, if not millions, of years. Even locusts adapt to their environment using complex, evolving strategies that involve epigenetic changes—alterations in gene activity influenced by factors like age and the environment—allowing them to switch rapidly between calm green forms and swarming yellow-and-black forms when population density rises.
These findings have revealed that not only do animals exhibit forms of culture, but they also show signs of cultural accumulation, a trait once thought to be exclusive to humans.
Morgan stated, “It was once believed that other species lacked culture entirely. Now we know that many species possess it. Initially, it was thought that only human cultures could accumulate and evolve over time, but we’ve discovered that animal cultures can too. So, if animals do have evolving cultures, what makes human culture stand out?”
Open-endedness
In their recent paper titled “Human Culture is Uniquely Open-ended Not Uniquely Cumulative” published in Nature Human Behaviour, Morgan and Stanford University Professor Marcus Feldman offer a new perspective. They suggest that what sets humans apart is our “open-endedness”—the ability to communicate and comprehend an endless array of possibilities in life.
Morgan explained, “The cognitive limitations of animals may restrict the evolution of their cultures. They might struggle to conceptualize complex sequences or subgoals.”
He illustrated this by comparing it to making breakfast for his children: “It’s a complex, multistep process. First, I gather the bowls, pots, and other equipment. Next, I add ingredients to the pot and start cooking them in the correct amounts and order. I then monitor the cooking process, stirring and adjusting temperature until achieving the right consistency before serving.”
He continued, “Each of these steps serves as a subgoal, containing more specific steps that I must accomplish in a particular sequence, thus forming a detailed procedure.”
In terms of cognitive limits, human brains continuously adapt, enabling us to create and follow intricate sequences of instructions, allowing for a nearly limitless range of actions—this is what we call open-endedness.
Beyond Culture
While previous comparisons between human and animal cultures have occurred, Morgan and Feldman’s research stands out by also evaluating animal instances of epigenetic inheritance and parental influences. The leafcutter ant serves as an example of parental effect, while the locust exemplifies cumulative epigenetic inheritance.
Though both forms of inheritance and parental influences remain stable and accumulate in non-human species, they eventually reach a developmental plateau, as noted by Morgan. “Like animal cultures, these systems face limitations that impede their ongoing evolution.”
“The crucial question is what is distinctive about human culture. We sought to answer this by contrasting human cultures with animal cultures, epigenetics, and parental influences—examining various evolving systems. In conclusion, we determine that the uniqueness of human culture lies in its open-endedness. It can accumulate indefinitely, never ceasing its evolution.”
