Human beings inherit many genetic traits directly from their parents. However, cultural traits — tools, beliefs and behaviors that are transmitted by learning — can be passed on not only by parents but also teachers and peers. Many animals have learned behaviors, but people are uniquely good at building on existing knowledge to innovate further. This capacity, known as cumulative culture, was captured by Sir Isaac Newton when he said, “If I have seen further, it is by standing on the shoulders of giants.”
We can see evidence of this cumulative culture in the archaeological record; over time, there’s an accelerating increase in the number of tools people use. But the archaeological record reveals another pattern, too: there’s also evidence for large-scale losses of culture. For example, archaeological excavation suggests that Aboriginal populations in Tasmania lost numerous technologies over time, including nets, bone tools and warm clothing, even though these tools might still have been useful.
And it doesn’t seem like cultural accumulation just proceeds through time at a regular pace. The archaeological record shows some evidence of large bursts of innovation occurring after relatively long periods of little change. For example, the early human archaeological record is composed primarily of stone tools for approximately two million years. Then, from about 60,000 to 30,000 years ago, archaeologists find a burst of creative activity, such as burial sites, art forms including cave paintings and statues, and engraved bone and antler tools.