Living Reference Work Entry

Encyclopedia of Evolutionary Psychological Science

pp 1-4

Date: Latest Version


  • Ivo JacobsAffiliated withLund University
  • , Mathias OsvathAffiliated withLund University Email author 


Borderline tool


Proto-tools are functionally analogous to tools but are not held and directly manipulated during or prior to use. (Shumaker et al. 2011)


An ancient prophecy once foretold that Aeschylus, the Greek playwright, would die by something falling on his head. He therefore spent the entirety of this cursed day in an open field, far from buildings, trees, and anything else that could fall on his head. Alas, he could not escape his destiny because an eagle dropped a tortoise on his head. If the eagle intended to kill him, this would be classified as tool use. However, it is possible she simply aimed for a nearby rock, or mistook the poet’s shiny bald head for one, in order to crack the tortoise’s hard shell. This would be classified as proto-tool use because the supposed tool (rock or head) was not held or manipulated by the eagle (Shumaker et al. 2011).

Defining tool use is an ongoing challenge that includes distinguishing it from similar behaviors suc ...

This is an excerpt from the content