Teaching to make stone tools: new experimental evidence supporting a technological hypothesis for the origins of language

In the paper

“Furthermore, some authors claim that the application of the alternating method generates more invasive flakes, that is to say, flakes that penetrate more deeply towards the inside of the blank, allowing for the extraction of more cortical surface42,49.”

What the sources say

• Partly supported

  In “Core Technology at Botany Pit” (page unavailable), the paper says alternate flaking tends to be invasive, removing material from the body or volume of the core. It does not say this allows more cortical surface to be removed. (LLM, conf=0.86)

  cites [42] White, M. J. & Ashton, N. M. Lower Paleolithic core technology and the origins of the Levallois method in North-WesternEurope. Cur. Anthr. 44, 598–609 (2003). sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [49] Moore, M. W. Australian aboriginal biface reduction techniques on the Georgia River, Camooweal, Queensland. Austral. Arch. 56, 22–34 (2003). source

In the paper

“However, the results of Morgan et al. indicate that gestural communication, and especially verbal communication, are more effective than non-teaching conditions (reverse engineering or imitation-emulation)39.”

What the sources say

• Supported

  The Results (Performance across conditions) report that gestural and verbal teaching improved stone-knapping performance relative to reverse engineering, while imitation/emulation showed little evidence of improvement. They also report strong evidence that verbal teaching improved performance relative to gestural teaching. (LLM, conf=0.94)

  cites [39] Morgan, T. J. H. et al. Experimental evidence for the co-evolution of hominin tool-making teaching and language. Nat. Commun. 6, 6029 (2015). source

In the paper

“The imitation-emulation volunteers produced flakes with thinner platforms, while the flake platforms of the verbal and gestural communication groups were thicker, more like to those of the skilled knapper. This may indicate that more adequate percussion platforms were selected by these groups compared with the imitation-emulation knappers73.”

What the sources say

• ?Could not verify

  Split into 2 atoms — 0 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 2 unverifiable. Expand the claim to see per-atom verdicts.

  cites [73] Lewis, H. M. & Laland, K. N. Transmission fidelity is the key to the build-up of cumulative culture. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 367, 2171–2180 (2012). sourceExperimental — accuracy not yet measured

In the paper

“although it is well known that the initial morphology of a blank strongly influences the final products41,42.”

What the sources say

• ?Not checked — no full text of the sourcecites [41] Guardiola, M., Morales, J. I. & Vergès, J. M. From blunt to cutting: Distinguishing alternating method flakes in early stages on rounded blanks. Quat. Intern. 411, 378–385 (2016). source
• Partly supported

  The Discussion (page unavailable) says biface surface forms depend in part on the blank type used, supporting an influence of the starting blank on the resulting form. It does not establish that initial blank morphology strongly influences final products generally; the same section describes whether blank shape dictates certain core techniques as debatable. (LLM, conf=0.80)

  cites [42] White, M. J. & Ashton, N. M. Lower Paleolithic core technology and the origins of the Levallois method in North-WesternEurope. Cur. Anthr. 44, 598–609 (2003). sourceExperimental — accuracy not yet measured

In the paper

“This body of study comprises evidence supporting the technological hypothesis of the origin of language, and particularly the technological pedagogy hypothesis6, which contends that intentional pedagogical demonstration may have spurred the evolution of the verbal communication24.”

What the sources say

• Supported

  Split into 2 atoms — 2 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [6] Stout, D. & Chaminade, T. Stone tools, language and the brain in the human evolution. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 367, 75–87 (2012). source
• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [24] Csibra, G. & Gergely, G. Natural pedagogy as evolutionary adaptation. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 366, 1149–1157 (2011). sourceExperimental — accuracy not yet measured

In the paper

“In this regard, the results of our study and other research39 indicate that teaching, especially by means of verbal communication, is the most effective social transmission mechanism for learning lithic knapping, and is especially helpful for acquiring and retaining concepts such as core rotation and turning, using negatives of previous blows as percussion platforms for subsequent extractions.”

What the sources say

• Partly supported

  The Results (Performance across conditions; page unavailable) find that teaching, particularly verbal teaching, improved transmission of Oldowan flaking skills. The Discussion (page unavailable) names demonstrating core rotation as a teaching technique and says verbal instruction transmitted abstract concepts such as platform angle. The paper does not establish improved acquisition or retention of core turning or the use of negatives from earlier blows as percussion platforms. (LLM, conf=0.87)

  cites [39] Morgan, T. J. H. et al. Experimental evidence for the co-evolution of hominin tool-making teaching and language. Nat. Commun. 6, 6029 (2015). sourceExperimental — accuracy not yet measured

In the paper

“This would have allowed limited transmission among individuals maintaining long-term duration contacts, but would restrict the emergence of innovations and the dissemination speed39 of more organised methods of core reduction.”

What the sources say

• Partly supported

  The Discussion (page not provided) suggests that low-fidelity transmission could have slowed the spread of Oldowan technology and prevented innovations from spreading; it also says observation alone is an inefficient way to acquire stone-tool-making skills. It does not address transmission specifically among people with long-term contacts or the spread of more organised core-reduction methods, and it presents the restriction on innovation as a possibility rather than a certainty. (LLM, conf=0.83)

  cites [39] Morgan, T. J. H. et al. Experimental evidence for the co-evolution of hominin tool-making teaching and language. Nat. Commun. 6, 6029 (2015). sourceExperimental — accuracy not yet measured

In the paper

“It would also have been beneficial for developing skills requiring coordinated actions by multiple individuals, such as collective defence80.”

What the sources say

• Supported

  The passage labeled Abstract explicitly includes collective defense among skills whose teaching would benefit from verbal instruction, and says some of those skills required coordinated actions by multiple individuals. This supports the citing sentence’s qualified claim. (LLM, conf=0.94)

  cites [80] Laland, K. N. The origins of language in teaching. Psychon Bull Rev. 24, 225–231 (2017). source

In the paper

“The pattern in both phases is the same: the expert knapper is closely related to successful extractions, while the imitation-emulation group is characterized by percussions without extraction. Both the gestural and verbal communication groups are in an intermediate range, with no clear differences between them (see Fig. 1).”

In the paper

“Besides the gestural and verbal communication groups show similar striking platforms, there are statistical significant differences between the verbal communication group and the imitation-emulation and gestural communication groups, either in the thickness of the flakes (K-W IE-V (p) = 0.003855; K-W G-V (p) = 0.005541), and the carenate index (K-W IE-V (p) = 0.000000433; K-W G-V (p) = 0.001969).”

In the paper

“Although we found no clear differences in core perimeter, the expert knapper exploited the cores more fully, that is, he extracted more mass per core, as shown by the mean of the Extracted Mass Indexes obtained for his cores (EMI EK) = 0.76). The verbal communication group produced the EMI most similar to that of the expert knapper (EMI V = 0.71), followed by the gestural communication group (EMI”

In the paper

“Striking differences arise when differentiating the results according to the phase of the experiment in which they were produced: although the general tendency in all groups was to produce fewer alternating flakes in Phase 2 than in Phase 1, there were differences in the intensity of these decreases.”

In the paper

“The verbal group showed a slight decrease from 88.40% in Phase 1 to 80% in Phase 2, getting in both phases a percentage very similar to the expert (90% of consecutive flakes) (Fig. 3B).”

In the paper

“The correlation between the cortical surface remaining in the cores and the extracted mass –that is, working out the area of the removals regarding the total surface of the core-, inform about how invasive (marginal or deep) are the flakes relative to the extracted mass. This correlation shows further differences between the skilled knapper and the apprentices, as well as between the different”

In the paper

“In the gestural group, there was a decrease from 85.14% of consecutive flakes in Phase 1 to 52.91% in Phase 2, the latter being very similar to the imitation-emulation group (48.15% in Phase 1 and 54.36% in Phase 2).”

In the paper

“Our results show that the apprentices improved their knapping skills in teaching conditions -both gestural and verbal communication-, and specially through the latter.”

In the paper

“All three groups started with identical blanks, and we found no clear differences in the general morphology of the final products (flakes). On the other hand, the most evident differences were seen during the knapping process: in technical abilities (reflected in the number of percussions and extractions made), and in the knapping sequences.”

In the paper

“A total of 1674 flakes and 90 cores were produced during the experiment. The skilled knapper generated 629 flakes and 30 cores; the imitation-emulation apprentices produced 357 flakes; the gestural communication apprentices generated 347 flakes; and the verbal communication apprentices obtained 341flakes (Fig. 4). Each learning group produced 20 cores (Fig. 5).”

In the paper

“In the three learning groups, on average, the participants in the verbal communication group achieved a higher EfI (EfI V = 13.99) than the members of the gestural communication group (EfI G = 10.43), although these differences are not statistically significant (K-W G-V (p) = 0.07205).”

In the paper

“The results of the K-W test indicate that the differences between the verbal and gestural communication groups and the imitation-emulation group are statistically significant (K-W I-E-G (p) = 0.0239; K-W I-E-V (p) = 0.0003382).”

In the paper

“Furthermore, non-cortical platforms predominated in Phase 1 in the gestural group (Nco: 55.43%), while in Phase 2 completely cortical platforms predominated (Co: 59.3%) (Fig. 3c).”

In the paper

“Regardless of the type of social transmission, in this work we show that trainees never reached the level of results obtained by the expert knapper in terms of: 1) the number of hits performed to reduce the core; 2) the low percentage of percussions without extraction compared to the total number of percussions; 3) the relative weight of percussions with successful extractions; and finally, 4) the”

In the paper

“However, the differences between these groups and the imitation-emulation group are statistically significant in the number of percussions without extraction, both in the mean (Kruskal-Wallis test (p) <0.05) and distribution of values (Kolmogorov-Smirnov (p) <0.05) (Supplementary Material Table S4).”

In the paper

“The study of flake-core refitting and the subsequent reconstruction of the knapping sequences verified that the verbal communication group produced the highest number of alternating flakes (229), followed by the gestural group (112). In contrast, the imitation-emulation group produced only 13 alternating flakes (Table 2).”

In the paper

“When comparing the results from both faces of the cores, the skilled knapper tended to make more invasive removals in the first percussion face (face A, or second face of exploitation). This is established by the mean of the ratio between the cortical surface and the remaining mass on this face, which is much lower than that of the second face of percussion. In the gestural and verbal”

In the paper

“The most interesting difference among the learning groups is that while the verbal and gestural communication participants show thicker striking platforms, similar to those of the skilled knapper (K-W G-EK (p) = 0.9257; K-W V-EK (p) = 0.3566), the imitation-emulation group produced thinner percussion platforms, striking closer to the edge of the core.”

In the paper

“Finally, verbal communication plays a major role in the retention of knowledge on lithic knapping and the successful achievement of the alternating method, since the apprentice knappers enjoyed more than a 66% success rate in Phase 2 compared to Phase 1.”

In the paper

“In summary, in the early stages of apprenticeship, learning by imitation-emulation results in a limited success in flake production through a simple but systematic method, such as alternating knapping, and a little of the scarce knowledge acquired is retained, as the pronounced drop in learned information between Phase 1 and Phase 2 (about 63%) shows.”

In the paper

“Learning by gestures is a successful method for replicating the alternating method under the tuition of a master knapper, but it proves to be a somewhat inefficient mechanism of social transmission when it comes to retaining the information received (c. 9% of success in Phase 2 compared with Phase 1).”

In the paper

“Thirdly, the gestural and verbal communication groups selected their percussion platforms in much the same way that the skilled knapper did, whereas the imitation-emulation group did not.”

In the paper

“In conclusion, our study supports the hypothesis of co-evolution between lithic technology and social learning, which could have favoured the emergence of verbal language.”

In the paper

“Therefore, the “core rotation” and, particularly, “cortical area of the flake percussion platforms” variables best reflect the decreasing number of alternating flakes during the reduction process.”

In the paper

“Secondly, a complete reduction process, such as Levallois or bifacial knapping, actually includes various knapping methods and different ways of managing faces and sides. All of this leads to a huge diversity of options, making the chaînes opératoires very difficult to compare.”

In the paper

“Interestingly, we found no clear differences between the verbal and gestural communication groups at the technical capability level. Both communication types allowed the apprentice to focus on key gestural aspects of lithic knapping (such as percussion angle, percussion force, and so on). In contrast, the imitation-emulation group struggled to generate successful blows. This difficulty had an”

In the paper

“All the apprentice knappers carried out the experimental task with blanks that were equal in shape and size, and were requested to replicate what the expert knapper was doing: the alternating method, a sufficiently simple, but systematic technique for detaching flakes from a core.”

In the paper

“This could be why the gestural and verbal communication groups exploited the blanks to a greater degree and more effectively, than the apprentices in the imitation-emulation group. In addition, the communication groups presented lower ratios of cortical area/mass surface, because they produced more invasive flakes. Therefore, the gestural and verbal communication apprentices managed the blanks”

In the paper

“This underscores the need for more information about reduction processes, in order to determine the core reduction strategies used, and hence identify a knapper’s degree of experience from the archaeological record.”

In the paper

“None of the participants had prior experience of lithic knapping, and all had the same objective: to reproduce what the expert knapper was doing, i.e., the alternating method (Supplementary Material Table S1).”

• Also stated in: § Experimental design · plain

  “None of them had prior experience of lithic knapping.”

In the paper

“Our experimental programme involved 30 participants, ranging in age between 20 and 42, randomly divided into three groups of ten individuals each, according to the learning conditions to be imposed during the experiment: 10 volunteers for the imitation-emulation condition, 10 volunteers for the gestural-communication condition and 10 volunteers for the verbal communication condition.”

In the paper

“It is more effective because much more information is transmitted; and more efficient because it achieves results in less time.”

In the paper

“In addition, very few studies have focused on identifying significant attributes of this method in flakes41.”

What the sources say

• ?Not checked — no full text of the sourcecites [41] Guardiola, M., Morales, J. I. & Vergès, J. M. From blunt to cutting: Distinguishing alternating method flakes in early stages on rounded blanks. Quat. Intern. 411, 378–385 (2016). source

In the paper

“Beyond this, verbal communication, unlike gestural communication, allows for the use of concepts such as “percussion platform”, which facilitates the understanding and retention of this knowledge, thereby favouring its subsequent use by the apprentices.”

In the paper

“This effectiveness lies in the fact that both mechanisms (gestural and verbal) facilitate learning by centring the learner’s attention both on the gestural aspects of lithic knapping (i.e., flaking paths, percussion angles, and so on), and theoretical aspects (i.e., understanding and applying the alternating method).”

In the paper

“These were randomly divided into three groups of 10 individuals each, to study the knapping techniques through imitation-emulation, gestural-communication, and verbal-communication.”

In the paper

“Therefore, the raw material was identical for each volunteer and all volunteers had the same opportunities.”

In the paper

“As Morgan et al., suggest the relative simplicity and duration of the knapping processes from the early technocomplexes, such as the Oldowan, may indicate learning by direct observation.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Morgan et al.

In the paper

“We decided to use commercial bricks as raw material because they display conchoidal fracture, allow the variables of the initial blank morphology to be controlled, and are safe for inexperienced knappers.”

In the paper

“However, identifying the alternating method in the archaeological record is difficult without the presence of refits.”

In the paper

“Nevertheless, lithic technology is not the only area in which more effective social transmission would have been advantageous.”

In the paper

“For example, language would have been beneficial for the acquisition of other key knowledge in terms of subsistence, including hunting, scavenging, food processing, control of raw materials and water supplies.”

In the paper

“Each participant was briefed on the experimental procedure and their consent for the participation in the study and the publication of images of the procedure was required to proceed.”

In the paper

“All the experiments were performed following the institutional guidelines and regulations for ethical approval (IPHES-URV sim. PGPRL-04-01).”