Making stone tools likely relates to learning speech.

Evidence

All the carefully focused and planned creativity required to make this axe implies an enormous advance in how our ancestors saw the world and how their brains worked. … The handaxe may also contain the evidence of something even more remarkable: this chipped stone tool may hold the secret of speech, and it may have been in making things like this that we learnt how to talk to one another. — Neil MacGregor, A History of the World in 100 Objects, 96

Categorization

• corroborated: 2 independent passages support this claim — Neil MacGregor, A History of the World in 100 Objects, 96
• XREF: connects to: Neurological studies show overlapping brain areas for stone tool making and speaking. — Neil MacGregor, A History of the World in 100 Objects, 97; Stone tool food-processing began at least three million years ago. — Joseph Henrich, The Secret of Our Success: How Culture…, 231; Rocks become meaningful when traced to their role in human origins — Freeman Tilden, Interpreting Our Heritage, 605

Library Connections

• Neurological studies show overlapping brain areas for stone tool making and speaking. #expands (0.90) — Neil MacGregor, A History of the World in 100 Objects, 97