ORIGINAL SOURCE: While Easter Island was divided into about eleven territories, each belonging to one clan under its own chief and competing with other clans, the island was loosely integrated religiously, economically, and politically under the leadership of one paramount chief. On other Polynesian islands, competition between chiefs for prestige could take the form of inter$-$island efforts such as trading and raiding, but Easter's extreme isolation from other islands precluded that possibility. Instead, the excellent quality of Rano Raraku volcanic stone for carving eventually resulted in chiefs competing by erecting statues representing their high$-$ranking ancestors on rectangular stone platforms $($termed ahu$).$

From Diamond, J$.(2004,$ March $25).$ Twilight at Easter $[$Review of the books The enigmas of Easter Island and Among stone giants: The life of Katherine Routledge and her remarkable expedition to Easter Island$].$ New York Review of Books, $51(6),8-10.$ The source paragraph appears on page $8.$

QUESTION: Based on the passage above, is this sentence properly cited or plagiarized? Here's the sentence: According to Diamond $(2004),$ rivalries between Polynesian rulers for status sometimes took the form of island$-$to$-$island endeavors like commerce or invasions.

Properly Cited

Plagiarized