Recent Research Projects and Publications

Here I only highlight the projects conducted after 2009. Projects and publications prior to 2009 were completed in China and written in Chinese, the list of which can be found in my CV.

Project #1. Neolithic earth-working implements and land-use strategies in the Lower Yangzi River

This was my doctoral project conducted during 2009-2013. Drawing ideas from Human Behavioral Ecology and Behavioral Archaeology, this project explored technological, economic, and social developments associated with intensified agricultural land use and sedentary settlements. I used soil science, micro-wear analysis, ethnography, zooarchaeology, and controlled experiments to explain technological choices among alternative forms of earth-working implements. I concluded that cultural transmission through craft production, rather than economic decisions, ensured the persistence of bone spades in the Neolithic technological repertoire. The resultant technological tradition established a long-lasting technical and conceptual framework for communities' land-use strategies.

I have published five peer-review journal articles from this project. The methods developed in each of these articles are applicable beyond the study region. Xie et al. 2015 developed new methods for measuring the costs of ancient construction projects. The metric of cost includes not only time and caloric consumption, but also tool attrition that was previously unstudied. It reveals that, in addition to labour for construction, the demands on earth-working implements and associated craftspeople for large-scale prehistoric earthworks were substantial. These findings opened new doors and created a solid foundation for examining the relationship between large construction projects, craft production, and power integration in prehistory. In this article, I also devised analytical tools for tackling questions about perceptions of technological differentiation, using a unique combination of qualitative and quantitative measurements.

Xie et al. 2017 combined micro-wear analysis and soil analysis to develop a reliable dataset for identifying osseous agricultural tools from the archaeological record. The results show that in the Neolithic Hemudu communities in the Lower Yangzi Basin, agricultural implements were less frequently employed and less durable than previously thought. The Hemudu people’s choice of farming tools crafted from bone played a role in shaping their strategic thinking about agricultural land use. These results added new evidence to challenge the dichotomous categories of farmers and foragers, supporting the argument that the Neolithic Hemudu people were low-level food producers or ecological engineers. The analytical tools developed in this research also added a new line of inquiry for the emergence and intensification of agriculture in the past.

Xie and Stiner 2018 developed new approaches to identify animal age structure based on skeletal elements that normally would not be considered for distinguishing among adult age classes. The results show that Neolithic communities were highly selective about bone raw materials even when the preferred materials—those from older adult animals—were less commonly available to tool makers. Our data also demonstrate that the approaches developed in this research for reconstructing animal mortality patterns using water buffalo scapulae are applicable to other ungulate scapulae that have been transformed into tools or oracle bones in prehistoric and historic cultures.

Xie 2018 reconstructs the manufacturing procedure of the early Hemudu bone earth-working implements through replication experiments and accordingly assesses the costs of tool production within their behavioral contexts. The results revealed that the costs and benefits of technological choices were not equally perceivable to the decision-makers; the Hemudu tool producers made their technological choices based on easy-to-perceive advantages rather than comprehensive cost-benefit assessment. This research breaks the traditional academic boundaries between stone and bone artefacts, providing an exceptional archaeological case study in which the production patterns, tool kits, raw material availability, technical styles, and social traditions were all taken into consideration for a more complete picture of technological organization and choices in prehistory.

Xie, Lun, et al. 2021 interprets the formation of the unique bone-shovel tradition in the Neolithic Hemudu communities from the perspective of cultural transmission and reveals a binary system of conformist style and material preference mixed with loose quality control in the bone-shovel production. The raw material preference and stylistic design mostly followed societal norms and were consistently transmitted through social learning, which likely became part of community identity and persisted even when the preferred raw material was much less available than alternative materials. Interestingly, when it comes to manufacturing, communities of practice were minimal to nonexistent among the shovel makers. Alternative mechanisms to maintain the technical norms or hold a high product standard were also lacking. the shovels were made by household crafters emulating from an artifact or a memorized template and had insufficient training and practice in manufacturing, resulting in repeated manufacturing mistakes and overall low to moderate quality of the implements. Therefore, we concluded that the bone shovels were less important as a technical implementation than a visual communicator of social identity.


Project #2. Settlement relocation, urban construction and social transformation in the Middle Yellow River valley

This project was stimulated by questions arising from Xie et al. 2015 about the importance of large-scale earthworks in reshaping social relationships, but situates the case studies in the Late Neolithic urban site of Taosi (2300-1900 BC) and Early Bronze Age site of Erlitou (c.1750-1520 BC) in the Middle Yellow River valley.

The project combines Placemaking Theory and Structuration Theory to interpret settlement data from the Jinnan Basins and Circum-Song Mts. Region in China’s Central Plain, and concludes that profound social changes occurred when substantial population movement combined with large-scale public work in the new place. Xie et al. 2020 addresses the theoretical relationship between settlement relocation and its sociopolitical consequences and uses the case of Taosi and Erlitou as examples to investigate the process of political knowledge-building regarding such a causal relationship at the dawn of China’s dynastic history. The article integrates all published settlement data in the study area and combines Placemaking Theory and Structuration Theory to interpret these data. Based on our assessment of settlement histories, divisions of space, burial patterns, and community formation, we conclude that the use of settlement relocation as a political strategy was formulated during the Taosi and Erlitou eras, and that it was intentionally implemented for political reform by Phase II of Erlitou.

Besides the theoretical dimension, this project also builds on my strengths in developing methods for estimating labour costs of ancient architecture through carefully conducted replication experiments. To generate reliable data for estimating labour costs for constructing the rammed-earth cities of Taosi and Erlitou (rammed-earth technology refers to tamping or pounding earth into a solid mass), I led a team of local workers to build a rammed-earth wall at Erlitou in the summer of 2017. The wall is 4 x 0.5 x 1.2 sq. m. above the ground and have a 4.3 x 1 x 0.5 sq. m. underground foundation. We constructed this wall with rammed-earth techniques based on my thorough examination of the relevant archaeological data. During this experiment, I used diverse parameters to quantify the qualities of the rammed-earth construction units in relation to the times and duration of tamping and the types of rammers employed and repeated the construction sessions with three workers multiple times to ensure the results capture a range of individual variations. With relevant data collected from the Taosi and Erlitou rammed-earth structures, I am able to interpret the tamping technology and the intensity of tamping employed in the ancient rammed-earth construction projects, permitting unprecedented accurate estimation of the labour involved in the ancient construction projects. The paper, Xie, Wang et al. 2021, is published in the Journal of Archaeological Science.

Moving forward, I am writing a book on urban construction and social transformation. This book will apply Placemaking Theory and Structuration Theory and the methods of architecture energetics to analyze all early urban sites constructed between the Late Neolithic and pre-Yinxu Shang Dynasty (3000 BC-1250 BC) in China’s Central Plain. If possible, it will also compare Chinese cases with examples from other world regions to identify the convergent and divergent trajectories to political complexification in the world’s early urban societies.


Project #3. Investigating ancient agricultural practices through micro-wear analysis of agricultural tools

This project was stimulated by the findings presented in Xie et al. 2017 regarding the Neolithic Hemudu communities’ agricultural practices detected from micro-wear patterns on bone earth-working implements. These findings, in addition to my intrinsic interest in studying ancient agriculture and advancing archaeological methods, motivated me to further investigate two questions. First, do stone earth-working implements, which are more common in the archaeological record than their bone counterparts used by the Hemudu people, also show distinctive micro-wear patterns in relation to their use? Second, is the observable distinction within earth-working wear quantifiable?

The research has thus far produced two publications in the Journal of Archaeological Science: Reports and one poster presented at the 82nd annual meeting of the Society for American Archaeology (SAA).

Xie, Gallo, and MacDonald 2019 addresses the first question. It reviews all published data in Chinese, English, and French regarding sediment properties’ influences on stone tools’ micro-wear appearance, and analyzes eight experimental implements that were used in a variety of earth-working contexts. The results provide the first comprehensive descriptions and interpretations of earth-working wear on ground stone implements and its variations in relation to sediment conditions. One of the most important findings is that earth-working wear is particularly sensitive to sediment texture and moisture level. Applying these results to studying the micro-wear patterns on ancient earth-working tools in the future can reveal sediment texture, assisting in recognizing ancient agricultural lands. The micro-wear patterns also reveal the moisture level of the farmland, providing the basis for identifying wet cultivation versus dry cultivation. This provides an important clue for clarifying when the Yellow River region—an area where the indigenous crop of millet requires dry farming—started adopting rice-growing technology rather than importing rice which originated from the Yangzi river region and requires wet farming.

My efforts to quantify earth-working micro-wear patterns involved two strategies, both representing the first applications of the relevant methods on a new tool type (earth-working implements) and a new raw material (either bone or heterogeneous stone) and have shown promising outcomes. MacDonald, Xie, and Gallo 2019 explores the applicability of quantitative microscopy—using a Sensofar S neox confocal microscope that was initially developed for precision engineering and surface metrology—to characterize the surface texture of micro-wear on four experimental hoes used for various durations and contexts. The results show that there are statistically significant differences between earth-working wear, hafting wear, and unused ground stone surfaces. The next step is to expand the dataset to test whether the quantitative microscope is capable of quantifying the qualitatively observable differences within wear types.

The SAA poster (Tsui and Xie 2017) employed an open-access image processing software ImageJ, which was developed in biology to analyze cell shapes, to quantify the micro-wear patterns shown on two-dimensional micro-wear pictures. The results show that ImageJ is able to isolate worn areas from non-worm areas, detect and measure micro-polish, and has the potential to differentiate highly developed earth-working wear derived from agricultural soils and non-agricultural soils. In the future, I plan to expand the poster into a peer-reviewed article. I also plan to compare the results from a number of software programs that have previously been employed in micro-wear analysis so as to identify the most cost-effective and reliable technical solution for quantitative use-wear analysis on photos.

Project #4. Seshat: Global History Databank

This project was established in 2011 by Dr. Peter Turchin from the University of Connecticut. It involves an ever-growing global team of social scientists and humanities scholars in a continuous effort to grow a gigantic web of data connected along temporal, spatial, and thematic dimensions in order to facilitate testing of theories about the evolution of complex societies during the period between the Neolithic and Industrial Revolutions. Additional information about the project can be found at:

I was invited to join the project in 2015 as an expert contributor on complex society in the Middle Yellow River region. So far I have co-authored in relevant publications: Thomas et al. 2018; Turchin et al. in press.