Ritual Offerings Under Lake Titicaca Reveal How Elites Used Religion to Form Ancient Tiwanaku Civilization

Late Titicaca archaeology
Typical Tiwanaku-Period offering in the Khoa reef. Teddy Seguin

An underwater excavation of Bolivia's Lake Titicaca has revealed extensive ritual offerings made by the early elite during the founding stages of the Tiwanaku state—a civilization established around 1,500 years ago that served as a major precursor to the Incan Empire.

Tiwanaku was based in the southern Lake Titicaca Basin. At its peak, its population was estimated to have been between 10,000 and 20,000. Scientists have now found out more about how this society emerged and thrived for almost 500 years.

In a study published in PNAS, Christophe Delaere, José Capriles and Charles Stanish report the results of underwater excavations carried out at the Khoa Reef in Lake Titicaca—an area where divers had previously found evidence of ritual offerings. Previously, archaeologists said the site had been important to Tiwanaku, with ritual offerings dating right up to the Inca Period. However, when the site started being a significant point for the civilization was unclear.

Instead of just collecting objects from the surface of the lake's bottom, the team carried out excavations to see what lay beneath: "That allowed us to sample a series of undisturbed contexts," Delaere and Capriles told Newsweek, adding that they hoped to find evidence of earlier offerings. That was exactly what they did. The team found hundreds of artifacts dating to the Tiwanaku period, including puma incense burners, gold medallions engraved with images of deities and semi-precious stone ornaments. They also found animal bones, including some from juvenile llamas, suggesting the animals had been killed in a ritual sacrifice.

At the time the Tiwanaku state was forming, the level of Lake Titicaca would have been lower, researchers say. As a result, there was likely a portion of the reef at the center of the lake that protruded from the water—providing an island platform from which the offerings could have been made. This, they say, is important.

"The ritual purpose of the site is undeniable. There is no evidence of human burials, so these deposits were made as offerings to the lake [as opposed to grave goods]. There are still many uncertainties about why this specific place was selected, but its central location within the lake is certainly significant," Delaere and Capriles said.

Lake Titicaca excavation
The underwater excavation unit used at Lake Titicaca, Bolivia. Teddy Seguin

"As society grew in size, securing trust among individuals becomes critical, and offering rich offerings to increasingly punishing deities—such as those represented by puma incense burners—provide a strong incentive for morally correct behavior. We believe it was elites who directed these rituals for two reasons. One, these are costly rituals and 'wasting' richly elaborated gold and lapidary objects is an expensive behavior that only wealthy individuals could have afforded. Two, the area is located in a remote reef within the lake and the offerings were likely carried out by a small group of people."

The team says the discovery of ritual offerings dating back to the start of the Tiwanaku civilization suggests religion played a vital role in the formation of the state, and that elites used their wealth to make offerings and thereby exert control over the rest of the population. As the society got bigger and started to adopt agriculture, individuals had to start cooperating and interacting with unknown individuals.

"Then it becomes increasingly difficult to trust these individuals as opportunities for 'cheating,' or benefiting from the collective labor without contributing, become increasingly frequent," they said. "Religion was probably emerged as a necessity to control freeloading behavior by rewarding those who do and punishing those who don't. In addition, individuals who signaled wealth were better positioned to define the mechanisms of behavior as wasting wealth is a strong honest signal.

"Individuals who were concerned about controlling power and economic surplus probably had greater incentives to engage in rituals that would promote moral behavior."

Concluding, the team says these elites were "more than a mere cult in an extreme location" and that they—like other emerging societies—adopted the idea of supernatural authorities to punish people, while also encouraging cooperation.

Lake Titicaca is home to far more archaeological sites and the team will continue to work there in order to discover more about its cultural importance. "One of the most remarkable sites includes a whole Tiwanaku village currently underwater and which, hopefully, will be the setting for an underwater museum," Mariano said.