Archaeologists have traced the development of religion in one location over a 7,000-year period, reporting that as an early society changed from foraging to settlement to the formation of an archaic state, religion also evolved to match the changing social structure. This archaeological record, because of its length and completeness, sheds an unusually clear light on the origins of religion, a universal human behavior but one whose evolutionary and social roots are still not well understood.
     The new findings are the fruit of 15 years of excavations in the Oaxaca Valley of southern Mexico by Dr. Joyce Marcus and Dr. Kent V. Flannery, two archaeologists at the University of Michigan. The Oaxaca Valley was home to people who around 7000 BCE were hunters and gatherers with no fixed abode. By 1500 BCE, the Oaxacans settled in villages that were occupied throughout the year. By 1150 BCE the first signs of social hierarchy appear, with an elite who lived in big houses. The Oaxacans flourished and in 500 BCE founded a populous and warlike society at Monte Albán known as the Zapotec state.
     The religious practices of each of these four stages of society can be inferred from the structures that the archaeologists have excavated and dated. At the hunter-gatherer stage, ceremonies took place on a plain dance floor, its sides marked by stones. The pre-Zapotec dance floor has been dated to 6650 BCE. A cave of the same period in a nearby valley has yielded the remains of individuals who appear to have been beheaded, cooked and eaten. Their remains were then buried with baskets of harvested wild plants, indicating that the human sacrifice that was such a notorious feature of later Mesoamerican cultures had ancient roots, possibly associated with harvest seasons.
     When the Oaxacans settled in permanent villages, their rituals became more formal. The Michigan archaeologists have excavated four men's houses, all oriented in the same direction, one that may have been determined by the sun's path at the spring equinox. This suggests the Oaxacans had formalized the ad hoc rituals of their forebears and now held their ceremonies at fixed times determined by the position of the sun or stars. By the third stage of society, marked by the emergence of elites, these men's houses had metamorphosed into temples. The temples were oriented in the same direction as the men's houses, but were now subject to a baroque system of two interlocking calendars, one of 260 days and one of 365 days, which came into synchrony once every 52 years.  By the time of the Zapotec state, the fourth stage of society, the temples had grown more complex, with special rooms for the new caste of religious officers, the priests.
     The religion of the Oaxacan people became both more elaborate and more exclusionary as society evolved, the archaeologists conclude. The hunter-gatherers' ritual dances would have been open to all, the men's houses were open only to initiated members of the public, and by the state stage, religion had come under the control of a special priestly caste.
     Why did religion evolve with society in this way? Anthropologists have advanced many different ideas about the role of religion, but a leading proposal is that it plays a cohesive role. Rituals were especially important in hunter-gatherer societies, which were egalitarian and had no chiefs or hierarchy to coordinate activities. Religion may have continued to serve as the principal source of cohesion in the first settled societies until they developed systems of political authority. But when elites and kings emerged, they did not dispense with the religious systems that were the previous source of social authority. Instead they employed religion as another mechanism of social control and as a means of maintaining their privileged position.
     The Michigan archaeologists believe that the ideas of a former colleague, the anthropologist Roy A. Rappaport, may explain several of their findings. Dr. Rappaport felt that religion, because of its universality, must have played some salient role in human evolution. He proposed that religion evolved with language as a means of certifying certain messages as true, and also of imposing some kind of order among those who bought into the idea. Sanctity, Dr. Rappaport wrote, "made it possible for early authorities to begin to command the men and control the resources that eventually provided them or their successors with actual power." Dr. Richard Sosis, an anthropologist at the University of Connecticut, said the Michigan archaeologists' study delineated the process of religion adapting to different environments as Oaxacan society changed. Among foragers, ritual serves to cement solidarity, he said, and the "powerful moralistic gods that we associate with contemporary religions" are a later development, introduced at the stage when priests have acquired control of a religion and "are effectively controlling the masses through ritual activities that instill the fear of supernatural punishment."

Source: The New York Times (21 December 2004)