Christianity's spread across the Pacific was enforced from the top-down, rather than spreading through some kind of social movement.
The finding is in a just-published study in the journal, Nature Science Communications, which studied 70 Austronesian cultures in the region.
The five authors wanted to know how Christianity grew from a tiny religious sect to one of the largest religions in the world.
"One theory is that Christianity has spread by a kind of top down process, where a leader converts and then sort of forces the people to convert - or at least strongly encourages them," explained one of the report's authors, Auckland University's Quentin Atkinson.
"This is sometimes argued to be what happened in Europe when Constantine converted to Christianity and then facilitated the spread of Christianity across Europe. But others have argued that actually the appeal of Christianity was from the bottom up. That it appealed to the kind of underclasses, who then forced the elites to themselves convert."
Professor Atkinson said with its recent - and well documented - conversions, the Pacific was a good place to study.
"We have this data on these 70 different cultures across the Pacific and they have different political structures, their cultures are different sizes - so different population sizes - and different levels of inequality," he said.
Professor Atkinson said the authors studied two hypotheses on Christianity's spread in the Pacific: whether leaders converted their people, or whether the people forced their leaders to convert.
"The test we applied was that if it's a top-down process, then those cultures that have a strong political structure with a clear leader are going to be more likely to convert more quickly. If it's a bottom-up process that appeals to the common person, then we predicted that conversion's going to be faster where there is more inequality," he said.
"We also thought that population size would play a role, so we put that in the models as well."
"So we looked at those three different factors and when we ran the analysis, we found that whether or not a society has a heirarchical political structure with a clear leader, does predict how quickly the society converts. They convert more quickly," he said.
"If you go back to some of records of the early missionaries, a couple of the successful missionaries actually explicitly talk about deliberately targetting the leaders because that's where they see the power," Professor Atkinson said. "The level of inequality didn't affect the conversion type. So that supports the top down argument."
The spread of Christianity throughout the Pacific also coincided with the establishment of trade routes and European colonisation of the region, and Professor Atkinson said it was difficult to seperate them.
"But I guess when you're looking at a large number of groups all with slightly different conditions you can kind of average out some of the variation in colonial strategy and just look at the differences in conversion times."