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How can ten fingers shape a pot? Evidence for equivalent function in culturally distinct motor skills.

Gandon E, Bootsma RJ, Endler JA, Grosman L - PLoS ONE (2013)

Bottom Line: In analysing motor behaviour it is useful to distinguish how the action is performed from the result achieved.As expected, results revealed a cultural influence on the operational aspects of the potters' motor skill.Yet, the marked cultural differences in hand positions used did not give rise to noticeable differences in the shapes of the vessels produced.

View Article: PubMed Central - PubMed

Affiliation: Computerized Archaeology Laboratory, Institute of Archaeology, Jerusalem, Israel.

ABSTRACT
Behavioural variability is likely to emerge when a particular task is performed in different cultural settings, assuming that part of human motor behaviour is influenced by culture. In analysing motor behaviour it is useful to distinguish how the action is performed from the result achieved. Does cultural environment lead to specific cultural motor skills? Are there differences between cultures both in the skills themselves and in the corresponding outcomes? Here we analyse the skill of pottery wheel-throwing in French and Indian cultural environments. Our specific goal was to examine the ability of expert potters from distinct cultural settings to reproduce a common model shape (a sphere). The operational aspects of motor performance were captured through the analysis of the hand positions used by the potters during the fashioning process. In parallel, the outcomes were captured by the geometrical characteristics of the vessels produced. As expected, results revealed a cultural influence on the operational aspects of the potters' motor skill. Yet, the marked cultural differences in hand positions used did not give rise to noticeable differences in the shapes of the vessels produced. Hence, for the simple model form studied, the culturally-specific motor traditions of the French and Indian potters gave rise to an equivalent outcome, that is shape uniformity. Further work is needed to test whether such equivalence is also observed in more complex ceramic shapes.

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Geometrical distributions of vessels thrown.The geometrical space is formed by the first two principal components of the PCA performed on the coefficients of the elliptical Fourier analysis of the vessel outlines. Blue open markers represent all vessels thrown by the French potters; green open markers represent all vessels thrown by the Indian Multani potters. Using the same colour code, the 95%-confidence ellipses are superimposed, with their principal axes and centroids (solid markers). The solid black markers represent the model shape. Panel A: Small 0.75 kg spheres. Panel B: Large 2.25 kg spheres.
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pone-0081614-g004: Geometrical distributions of vessels thrown.The geometrical space is formed by the first two principal components of the PCA performed on the coefficients of the elliptical Fourier analysis of the vessel outlines. Blue open markers represent all vessels thrown by the French potters; green open markers represent all vessels thrown by the Indian Multani potters. Using the same colour code, the 95%-confidence ellipses are superimposed, with their principal axes and centroids (solid markers). The solid black markers represent the model shape. Panel A: Small 0.75 kg spheres. Panel B: Large 2.25 kg spheres.

Mentions: Figure 4 presents the geometrical characteristics of the vessels thrown by the French and Multani groups, for the small and large sphere conditions separately, in the two-dimensional PC-space. Visual inspection revealed that the distributions of small spheres (Figure 4A) were reasonably well centred on the geometry of the model shape. For the large spheres (Figure 4B), however, the centre of the distributions deviated to a certain extent from the model geometry. Surprisingly, for both masses, the French and Multani assemblages displayed a fair degree of similarity, in both the location and the orientation of the distributions in PC-space, indicating common shapes. The MANOVA confirmed the observations with respect to location in PC-space, as Mass was found exert a significant influence (F(2, 10) = 7.47, p < 0.01) while Group did not (F(2, 10) = 1.28, ns). Thus, the French and Indian potters produced vessels of equivalent shape when throwing the same amount of clay. However, for both groups, the shape of the vessels varied with the amount of clay used.


How can ten fingers shape a pot? Evidence for equivalent function in culturally distinct motor skills.

Gandon E, Bootsma RJ, Endler JA, Grosman L - PLoS ONE (2013)

Geometrical distributions of vessels thrown.The geometrical space is formed by the first two principal components of the PCA performed on the coefficients of the elliptical Fourier analysis of the vessel outlines. Blue open markers represent all vessels thrown by the French potters; green open markers represent all vessels thrown by the Indian Multani potters. Using the same colour code, the 95%-confidence ellipses are superimposed, with their principal axes and centroids (solid markers). The solid black markers represent the model shape. Panel A: Small 0.75 kg spheres. Panel B: Large 2.25 kg spheres.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3842241&req=5

pone-0081614-g004: Geometrical distributions of vessels thrown.The geometrical space is formed by the first two principal components of the PCA performed on the coefficients of the elliptical Fourier analysis of the vessel outlines. Blue open markers represent all vessels thrown by the French potters; green open markers represent all vessels thrown by the Indian Multani potters. Using the same colour code, the 95%-confidence ellipses are superimposed, with their principal axes and centroids (solid markers). The solid black markers represent the model shape. Panel A: Small 0.75 kg spheres. Panel B: Large 2.25 kg spheres.
Mentions: Figure 4 presents the geometrical characteristics of the vessels thrown by the French and Multani groups, for the small and large sphere conditions separately, in the two-dimensional PC-space. Visual inspection revealed that the distributions of small spheres (Figure 4A) were reasonably well centred on the geometry of the model shape. For the large spheres (Figure 4B), however, the centre of the distributions deviated to a certain extent from the model geometry. Surprisingly, for both masses, the French and Multani assemblages displayed a fair degree of similarity, in both the location and the orientation of the distributions in PC-space, indicating common shapes. The MANOVA confirmed the observations with respect to location in PC-space, as Mass was found exert a significant influence (F(2, 10) = 7.47, p < 0.01) while Group did not (F(2, 10) = 1.28, ns). Thus, the French and Indian potters produced vessels of equivalent shape when throwing the same amount of clay. However, for both groups, the shape of the vessels varied with the amount of clay used.

Bottom Line: In analysing motor behaviour it is useful to distinguish how the action is performed from the result achieved.As expected, results revealed a cultural influence on the operational aspects of the potters' motor skill.Yet, the marked cultural differences in hand positions used did not give rise to noticeable differences in the shapes of the vessels produced.

View Article: PubMed Central - PubMed

Affiliation: Computerized Archaeology Laboratory, Institute of Archaeology, Jerusalem, Israel.

ABSTRACT
Behavioural variability is likely to emerge when a particular task is performed in different cultural settings, assuming that part of human motor behaviour is influenced by culture. In analysing motor behaviour it is useful to distinguish how the action is performed from the result achieved. Does cultural environment lead to specific cultural motor skills? Are there differences between cultures both in the skills themselves and in the corresponding outcomes? Here we analyse the skill of pottery wheel-throwing in French and Indian cultural environments. Our specific goal was to examine the ability of expert potters from distinct cultural settings to reproduce a common model shape (a sphere). The operational aspects of motor performance were captured through the analysis of the hand positions used by the potters during the fashioning process. In parallel, the outcomes were captured by the geometrical characteristics of the vessels produced. As expected, results revealed a cultural influence on the operational aspects of the potters' motor skill. Yet, the marked cultural differences in hand positions used did not give rise to noticeable differences in the shapes of the vessels produced. Hence, for the simple model form studied, the culturally-specific motor traditions of the French and Indian potters gave rise to an equivalent outcome, that is shape uniformity. Further work is needed to test whether such equivalence is also observed in more complex ceramic shapes.

Show MeSH