In this dissertation, I examine trajectories of cultural evolution among complexhunter-gatherers and middle range societies. Broadly, I consider the theoretical issuesrelated to these two areas of study and how we should conceptualize the study of socioculturalevolution in societies organized at this scale. I apply these ideas to the study ofthe prehistoric hunter-gatherers who occupied Sapelo Island, Georgia, U. S. A.Specifically, I examine the Archaic period (4200 – 3000 B. P.) occupation of the SapeloShell Ring complex, located on the western side of the island. In particular, I study issuesof sedentism, settlement aggregation, mound construction, and the emergence of socialinequality as they relate to shell rings in the southeastern United States, as well as otherareas of the world. One of the central problems for studying these sites is whether shellrings form by gradual accumulation or by intentional construction and the concomitantsocial formations associated with these two different behaviors. Using geophysicalsurvey, artifact distributions, and radiocarbon dating, I examine the use and nature ofspace at the site as well as site formation processes. I present the results of both thegrowth band analysis on clams and the isotopic analysis on clams and oysters from thesite in order to address season of occupation. In addition to this new data, a reanalysis ofprevious excavations is presented. Combined, these data lend important insights intodifferent dimensions of socio-political complexity. Specifically, these data suggest thatthe Sapelo Shell Ring complex population was relatively large for its time. It addition, itseems that at least some portion of the population occupied the site year-round. Despiteit large population size and reduced mobility the occupants of the site maintained at leastsome degree of egalitarian social relations.

The Green River region of western Kentucky has been a focus of Archaic period research since 1915. Currently, the region is playing an important role in discussions of Archaic hunter-gatherer cultural complexity. Unfortunately, many of the larger Green River sites contain several archaeological components ranging from the Early to Late Archaic periods. Understanding culture change requires that these multiple components somehow be sorted and addressed individually. Detailed re-analyses of Works Progress Administration (WPA) era artifact collections from two archaeological sites in the Green River region – the Baker (15Mu12) and Chiggerville (15Oh1) shell middens – indicate that these sites are relatively isolated Middle and Late Archaic components, respectively. The relatively unmixed character of Baker and Chiggerville makes these sites excellent candidates for evaluating aspects of complexity during the Archaic. After developing a theoretical basis for evaluating the relative complexity of the social organization of the Baker and Chiggerville site inhabitants on the basis of the material record they left behind, I employ detailed analyses of the bone, antler, and stone tools from these two sites to examine six microscalar aspects of complexity – technological organization, subsistence, specialization, leadership, communication networks, and exchange. These microscalar aspects of complexity all can be linked materially to the archaeological record of the Green River region and can be evaluated as proxies for changes in social organization among the hunter-gatherers who inhabited this region during the Middle and Late Archaic periods. Although the Baker assemblage indicated greater complexity in communication networks and certain proxies for leadership and technological organization, most indicators suggest that the Chiggerville site inhabitants were the more complexly organized group and were in the process of developing a tribal-like social formation. This research, therefore, tentatively supports the hypothesis of increasing complexity through time during the Archaic. However, marked differences in the technological strategies utilized by the Baker and Chiggerville site inhabitants indicates these groups may not have been historically related, thereby violating one of the primary assumptions of the project. If this alternative hypothesis is confirmed through additional research, then no conclusions concerning change through time can be derived from this study.

This study describes archaeological excavations carried out at Unguja Ukuu on the main island of Zanzibar, Tanzania. The site has long remained obscure, oral histories do not mention it and no particular group among the living community of the island describes its origin from the site. A stone well at Unguja Ukuu together with several other early monuments of the east African coast that survive on the site have been attributed to the Wadebuli, suspected by early scholars to be people of Arab descent from their colonies in India or elsewhere on the Islands of eastern Indian Ocean. Surface survey and the drilling of more than 200 cores have defined the lateral extent and the stratigraphy of the site. Unguja Ukuu is a large site (c.16–17 ha) and the study reveals that it is a major center of an African iron-using farming community who occupied it from c. 500 AD. Radiocarbon dating and pottery provide the basis for this chronology. The study addresses an old controversy whether some of the pre-stone built settlements that developed on the east African coast could be indications of urbanization. Knowledge of the functional specialization of the settlement prior to its abandonment c. 900 AD is based on the evidence on the density of craft activity, community engagement in the regional trade with the mainland African continent, as far away as Roman Egypt, and in the interregional trade connected to the Indian Ocean, as well as redistribution of foreign merchandise to other sites and areas in the region. These as well as the location of the site linking the external trade and the mainland resource base indicate that Unguja Ukuu was a key urban centre built of mud and timber structures. This challenges our previous understanding of 8–9th centuries AD as the onset of early urbanism on the east African coast. The study proposes cycles of urbanism and emphasizes the need to reassess the problem of early urban identity and the use of wide range of criteria to overcome limitations of previous early urban investigations south of the Sahara and beyond. The results of the investigation given in this study are relevant to the history and archaeology of Zanzibar and the rest of East Africa and make a contribution particularly to extending the known time depth of the early urban tradition often conceived to occur in the late first millennium ad.

There is something unique about human culture. Its complex technologies, customs, institutions, symbolisms and norms, which are shared and maintained and improved across countless generations, are what sets it apart from the ‘cultures' of other animals. The fundamental question that researchers are only just beginning to unravel is: How do we account for the gap between their ‘cultures' and ours? The answer lies in a deeper understanding of culture's complex constituent components: from the micro-level psychological mechanisms that guide and facilitate accurate social learning, to the macro-level cultural processes that unfold within large-scale cooperative groups. This thesis attempts to contribute to two broad themes that are of relevance to this question. The first theme involves the evolution of accurate and high-fidelity cultural transmission. In Chapter 2, a meta-analysis conducted across primate social learning studies finds support for the common assumption that imitative and/or emulative learning mechanisms are required for the high-fidelity transmission of complex instrumental cultural goals. Chapter 3, adopting an experimental study with young children, then questions the claim that mechanisms of high-fidelity copying have reached such heights in our own species that they will even lead us to blindly copy irrelevant, and potentially costly, information. The second theme involves investigations of the mutually reinforcing relationship predicted between cultural complexity and ultra-cooperativeness in humans, employing a series of laboratory-based experimental investigations with adults. Chapter 4 finds only limited support for a positive relationship between cooperative behaviour and behavioural imitation, which is believed to facilitate cultural group cohesion. Finally, Chapter 5 presents evidence suggesting that access to cultural information is positively associated with an individual's cooperative reputation, and argues that this dynamic might help to scaffold the evolution of increased cultural complexity and cooperation in a learning environment where cultural information carries high value.