The Tool Systems Approach: Measuring Complexity in the Primatological, Archaeological, and Ethnographic Records - Journal of Archaeological Method and Theory Measuring technological complexity across species, as well as across temporal and spatial scales, is an ongoing challenge among authors who work on primatological, archaeological, and/or ethnographic questions. Researchers in these individual fields have developed a number of innovative ways of approaching this issue that reflect the specific affordances of their data with a known set of limitations. However, comparability between these approaches is often difficult. One such field-specific approach is the techno-unit method of Oswalt et al. (1976), which has had a massive impact on our interpretation of ethnographic technology over the fifty years since its publication. Nevertheless, this method has issues with its compression of variability and the different pathways to “complexity”. Here, we review a number of different ways technological complexity has been measured in non-human primates, the archaeological record, and modern human foragers, in order to identify the relative strengths and weaknesses of each. We suggest that the approach deployed in any given study should continue to follow the data and research questions under consideration, but that we lack an easily-applicable method that allows explicit comparisons between fields of study. In this context, we introduce the Tool Systems Approach as one possible way of doing so, which decomposes tool manufacture into its constituent steps (i.e., Tool Systems Total) and discrete forms of action (i.e., Total Discrete Actions). We apply the approach to a number of different technologies across the three fields, to explore the practicalities of its application, as well as its limitations. Plotting these different technologies with regards to their maximum complexity through time reveals trends that may map onto important changes in cognitive evolution, which are also reflected in ever-growing variability in the complexity of individual artefacts. The ramifications for the study of technological complexity as a whole are discussed.

I am delighted to share our new paper on measuring complexity across the Primatological, Archaeological, and Ethnographic records, with an amazing team of co-authors - including the excellent @lucytimbrell96.bsky.social and @ceciliapad.bsky.social! Short 🧵 below /1

doi.org/10.1007/s108...

Out today making handaxes for an upcoming experiment. Always surprised by the frequency of canonical ‘blades’ - a useful reminder to not rely too heavily on typology!

Here’s the official record of the find for anyone interested:

finds.org.uk/database/art...

Been playing with clay silver which is magic! Here’s a ring impressed with a 13th century seal I found when I was a kid

I was going for La Ferrassie 1 when it started but stopped checking reference half way through so it’s not super Neanderthal-y!

Casts are too expensive so I am making terracotta skulls instead - this one with the help of Levallois flakes!

This demonstrates that Acheulean technology is not inherently high-investment, and maybe we should consider tools as expendable in some contexts. Particularly considering the biohazards of reusing butchery tools!

This could partially explain the massive accumulations of handaxes at some sites!

We also did ‘speed knaps’, with experts asked to make handaxes quickly as possible. While handaxes are often claimed to take as long as 30 mins to make, they can be made in seconds!

We recorded flaking sequences for 227 handaxes made by dozens of knappers! This gives us a grounded impression of time demands and potential ecological costs.

One clear (and unsurprising) result is that experienced knappers are more efficient, both in the number and intervals between strikes.

Acheulean Expediency Potential: Handaxe Manufacturing Time Costs, Covariates and Skill Despite decades of replicative experiments, the fundamental question “how long did it take to make an Acheulean handaxe” remains poorly understood. Archaeologists routinely base influential Pleisto...

New open access paper 🎉🎉

Acheulean Expediency Potential: Handaxe Manufacturing Costs, Covariates and Skill

www.tandfonline.com/doi/full/10....

The artwork that illustrated our PNAS paper on the oldest wooden tools was made by Gleiver Prieto, who has also worked with me on illustrations for previous projects, including the paleoenvironmental reconstruction of Marathousa 1.
Gleiver's art really brings Pleistocene Megalopolis to life ✨ 🤩

Evidence for the earliest hominin use of wooden handheld tools found at Marathousa 1 (Greece) | PNAS The Middle Pleistocene (MP; ca. 774 to 129 ka) marks a critical period of human evolution, characterized by increasing behavioral complexity and th...

It was such a privilege to get to work on this amazing material from an incredible site and team - now the earliest handheld wooden tools in the archaeological record, taking evidence back to 430,000 years! www.pnas.org/doi/10.1073/...

Technological innovations and hafted technology in central China ~160,000–72,000 years ago - Nature Communications Stone tools illustrate behavioural complexities in Middle Pleistocene hominin populations. Here, the authors present small dimensional flakes and hafted tools from Xigou, central China, dated to ~160–72 thousand years ago that demonstrate early, complex technological advancements.

Early humans in central China may have been making sophisticated stone tools as early as 160,000 years ago, according to research in Nature Communications. This discovery challenges the perception that stone tool technology in Asia lagged behind Europe and Africa during this period. 🏺 🧪

Rock art from at least 67,800 years ago in Sulawesi - Nature A hand stencil painted on a cave wall on a small island off the coast of Sulawesi more than 67,800 years ago suggests a very early occupation of Wallacea.

🧪🏺 WOWWWW
New dates in SE Asia for rock paintings - major implications:
- nature of early aesthetics, innovations
- relationship to oldest known Australian settlement?
- and (IMO) impacts claims that cave art in Europe >50 Ka is necessarily work of #Neanderthals
www.nature.com/articles/s41...

My mum just came back from a walk around a field with this, saying it’s probably not old but she wanted to show me just in case. It’s an early medieval stirrup mount! Landowner contacted and shortly off to local Finds Liaison Officer! Always worth keeping one eye on the ground!

Prehistoric tool made from elephant bone is the oldest discovered in Europe A remarkable prehistoric hammer made from elephant bone, dating back nearly half a million years ago, has been uncovered in southern England and analyzed by archaeologists from UCL and the Natural His...

More Breaking Palaeo-news!
🐘 Boxgrove preserved oldest Elephant Bone beyond Africa.
🐘 Early Neanderthals using bone to shape beautiful tools.
🐘 New research from Simon Parfitt @uclarchaeology.bsky.social Silvia Bello of the @nhm-london.bsky.social.
🦣🏺🐘https://share.google/20WUjY5TybDAr4QoT

Latest paper: Boxgrove is a key European site dating to 480,000 years ago. At GTP17, hominins knapped handaxes and then butchered an adult female horse. A fragment of the horse's scapula appeared to have evidence of impact from a wooden spear.....
www.sciencedirect.com/science/arti...

Please join us next week, Thursday 13h November, for our next talk. We will be joined by Finn Stileman, University of Cambridge. More details 👇

Please register here: liverpool-ac-uk.zoom.us/meeting/regi...
We hope to see you there!

Animal engravings

Animal engravings

Excavations

📣 PUBLISHED OPEN ACCESS 📣

An international team, including our own Finn Stileman, have published a new study in Nature Communications on a monumental rock art tradition in northern Arabia dating between 12,800 and 11,400 years ago.

www.nature.com/articles/s41...

📸 @finnstileman.bsky.social

New discovery! Here @mariaguagnin.bsky.social and our team report on 12,000-year-old life-size camel rock art engravings in the Saudi desert. #GreenArabia @griffith.edu.au www.nature.com/articles/s41...

Monumental rock art illustrates that humans thrived in the Arabian Desert during the Pleistocene-Holocene transition | Nature Communications Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Our new paper is out! www.nature.com/articles/s41... 12,000 year old camel engravings marked water sources in the desert. A great team effort @mdpetraglia.bsky.social @finnstileman.bsky.social @stewiestewart.bsky.social et al!

Was great to present a poster at #ESHE2025!

I commissioned it from Thalia Nitz Illustration!

While risk aversion can have short term benefits, this will limit long term skill acquisition and technological ceilings. We suggest that late Acheulean handaxe forms required tolerance of greater learning costs via deliberate practice, indicating 'mental time travel' and social support for learners

Simply, novices should cease knapping soon after a cutting edge is established, with further attempts at shaping tools tool increasing risk of a poor functioning tool. The novice rough-outs are similar in attrivutes to early Acheulean handaxes from Ubeidiya, which could reflect similar risk-aversion

Additionally, novice handaxes were more likely to break before completion, happening for 26% of attempts by novices and 7% for experts.

Edge crushing was recorded from handaxes and was three times higher on novice tools (1/3 of circumferences). Crushing % negatively correlates with rate of successful flakes for novices but not for experts. This indicates that knapping errors can be reversed by experts but they accumulate for novices

Recorded sequences of successful flake removals and mistrikes show clear differences between expert (top) and novice (bottom) knappers. Mistrike rate rapidly decreases for novices, outnumbered successful strikes by the end of the rough-out stage.

A PCA analysis of 3D shape and morphometric data show that expert handaxes improved much more than novices' from rough-out to final stages. Showing greater value of continued knapping for experts

We recruited 10 expert and 10 novice knappers, asking them each to replicate 4 flint handaxes, mimicking a target form. We 3D scanned handaxes as starting blanks, rough-outs (i.e. a biface prior to shaping) and finished forms. Flaking Sequences were also extrapolated from experiment footage.