Around 100,000 years ago, there is some evidence among homo sapiens of novel tool-making, such as bone artefacts. But the tools that were used and made then were not that much more sophisticated than our ape ancestors. The major turning point only occurred once homo sapiens had been around for tens of thousands of years. Mithen says the key challenge is to try to understand this explosion in creativity around 60,000 years ago, which doesn’t correspond with an increase in brain size – because that was a lot earlier. Brain capacity alone can’t explain this sudden leap forward.