(NewsNation) — When Cole McDowell turned 18, he was asked by The Church of Jesus Christ of Latter-day Saints (commonly known as the Mormon church) to serve as a missionary in El Salvador.

It was a big step for McDowell. While it is common for Latter-day Saints to serve on missions, he had never been so far outside the country. Growing up in Oregon, the only other country he had ever been to was Canada.

Growing up, the Spanish-speaking population he encountered was composed largely of migrant workers. He never got to know any of them very well. 

His service in El Salvador began in the summer of 2014 and concluded two years later. He formed bonds with the people he met, and befriended a young man studying to be a lawyer.

As violence raged across the country, the man he met made the decision to emigrate to the United States to seek safety.

Gang-driven violence in El Salvador was particularly severe between 2014 and 2015. While gangs are a persistent problem in many American cities, in El Salvador, gangs like MS-13 are powerful enough to rival local governments. It has often had the highest rates of homicide in any country that is not at war.

McDowell found himself becoming more sympathetic to the plight of immigrants who seek to come to the United States for a better life.

“It just kind of changed my perspective of what immigrants are … just kind of actually knowing people and the reasons they moved, it wasn’t just like, ‘oh, I want more money.’ It was like, ‘oh, I’m afraid I’m going to get killed here,’ basically,” he said.

Cole’s experience may be representative of the larger impact of the church’s missionary work, according to a study recently published in The Journal of Politics.

The church’s missions provide the ideal backdrop for an experiment about how being in a new social environment can change one’s attitudes because missionaries don’t choose the locations to which they are sent.

The study’s researchers note that this means that the experience “generates for each missionary random exposure to widely varying social contexts” — it’s not as if each missionary was eager to go to the specific region where they were assigned.

Researchers found missionaries sent to areas within the United States with more migrants of Latin American descent became considerably more tolerant toward undocumented immigrants following their service.

They also found that serving abroad in countries with substantial foreign-born populations was associated with developing more tolerant attitudes — for example, missionaries serving in Australia, where almost one-third of the population is foreign-born, changed their attitudes considerably more than missionaries who served in South Korea, where the percentage of foreign-born residents is in low single digits. Still, the biggest impacts were seen for missionaries who served in the United States.

Brigham Young University political scientist Chris Karpowitz, one of the study’s authors, emphasized that the fact these missionaries are going to these regions with the specific intent of engaging in community service may offer some insight into why their attitudes change, although it’s difficult to prove.

“We also think it’s important that the missionaries go to the new location with the specific goal of getting to know and serving the people there. … We don’t, however, have a comparison group that was sent to the same location without that service-based goal,” he said.

For McDowell, though, the impact of serving in El Salvador was undeniable.

“Just seeing that these were really good, smart people I cared about … made me want to be more compassionate to immigrants here in the U.S.,” he said.