The Evolution of Thought on the Evolution of Early Hominin Tool

Use Cognition

Where Do We Go from Here?

Shelby S. Putt

The University of Iowa

Are humans unique?

Are humans unique?

Flake byproducts produced from nut cracking

Intentional stone flaking by bonobo

• Early hominin stone tool technology dated to as early as 2.6 Ma in Africa

• Expedient method to obtain sharp flakes

The Oldowan tool industry

“…a communication system using symbolic language existed at least by the time of handaxes, if not before” (Holloway 1969:401).

“…the simplest known type of stone tools points indeed to the existence of…linguistic

capacities…” (Kitahara-Frisch 1978:2).

“I should like to see more attention devoted to what has given man his characteristic position on this planet: his tools and his language” (Hewes 1973:117).

“The grammatical precision of toolmaking at a level as old as Bed I at Olduvai strongly

suggests that speech was already well established among the makers of those

tools…” (Montagu 1976:270).

Views on Oldowan cognition then

(Psychology Press 2001)

Oldowan tool

manufacture

The ape adaptive grade

Views on Oldowan cognition now

= ?

Some researchers argue that there are more similarities than differences between the behaviors inferred from Oldowan tools

and ape tool use (e.g. Byrne 2004; Wynn et al. 2011).

Views on Oldowan cognition now

= ?

Others argue that a “cognitive leap” is evident from the sophistication of Oldowan tools (Toth and Schick 2009; de la Torre 2010).

The discovery of stone tools from

3.3 Ma may change the way we

view Pliocene hominin cognition.

Different stone fracturing techniques potentially used by

early hominins (Putt 2015)

Lomekwian tools produced by a) block-on-block and b)

bipolar techniques (Harmand et al. 2015)

A pre-Oldowan stage?

Verbal instruction is not necessary for acquiring the skills to make simple stone

tools (Putt et al. 2014).

Stone knapping neural activation under verbal conditions

(Stout and Chaminade 2007)

Cognition of social transmission

Left lateralization of frontal and parietal areas

Similar activation clusters to Stout et al. studies

Novel areas found include language and working memory areas

Hot colors = Knapping > Baseline; Cool colors = Baseline > Knapping

Neural correlates for knapping

Pilot results indicate that language instruction reorganizes the neural pattern for processing a learned

motor skill like knapping.

Hot colors = Nonverbal > Verbal; Cool colors = Verbal > Nonverbal

Social transmission and the brain

Non-interactive methods of social

transmission result in very low-fidelity

transmission of knapping skills.

(Morgan et al. 2015)

Cognition of social transmission

Where do we go from here?

An image of Oldowan cognition

An image of Oldowan cognition

What was hominin cognition like prior to the advent of the Oldowan industry?

How and when did linguistic abilities evolve?

What have cognitive archaeologists overlooked?

Gaps in our knowledge

Acknowledgments

Some of this work was made possible by…

The Wenner-Gren Foundation

The Leakey Foundation

Sigma Xi, The Scientific Research Society

The Department of Anthropology, the University of Iowa

The DeLTA Center, the University of Iowa