Hierarchical organization in tool use complexity

The idea is over 30 years old: Tool use based on some hierarchical organization with embedded clauses that that need action planning and could have been a structural precursor in the brain of our ancestors to allow for language to evolve. This idea, however, was hard to investigate empirically because we could not really compare across tool use tasks or across species. This method was now developed and tested. Please read here how can detect now hierarchical organized rules, how those are more complex than serial sequences and how we can compare across species boundaries, e.g. between chimpanzees and humans. Read https://rdcu.be/faxGa

Taylor D, Petersen1 T, Crockford C & Wittig RM (2026) Measuring hierarchical structure across hominid percussive tool-use sequences. Communications Biology https://doi.org/10.1038/s42003-026-09633-8