The moai and ahu were in use as early as AD 700, but the great majority were carved and erected between AD 1000 and 1500. Depending upon the size of the statue, between 50 and 150 people were needed to drag it across the countryside on sleds and rollers made from the island's trees. While many of the statues were toppled during the clan wars of the 1600 and 1700s, other statues fell over and cracked while being transported across the island. Recent research has shown that certain statue sites, particularly the most important ones with great ahu platforms, were periodically ritually dismantled and reassembled with ever larger statues. The meaning and purpose of these capstones is not known, but archaeologists have suggested that the moai thus marked were of pan-island ritual significance or perhaps sacred to a particular clan.
Scholars are unable to definitively explain the function and use of the moai statues.
It is assumed that their carving and erection derived from an idea rooted in similar practices found elsewhere in Polynesia but which evolved in a unique way on Easter Island. Archaeological and iconographic analysis indicates that the statue cult was based on an ideology of male, lineage-based authority incorporating anthropomorphic symbolism. The statues were thus symbols of authority and power, both religious and political. But they were not only symbols. To the people who erected and used them, they were actual repositories of sacred spirit.