In the largest ever academic study into belief in conspiracy theories, a team from the University of Cambridge polled people in nine countries to reveal how mainstream certain fringe conspiratorial views have become in recent years.

The research surveyed over 11,000 adults across the US, Britain, Poland, Italy, France, Germany, Portugal, Sweden, and Hungary. Subjects were asked about their beliefs across 10 different conspiracy theories, including whether alien contact with humans is being covered up by the government or climate change is a hoax.

Strikingly, over half of all respondents believed in at least one conspiracy theory presented to them. Sweden was the most skeptical country with 48 percent of people disbelieving every conspiracy presented, while Hungary was filled with the most believers with only 15 percent of people rejecting every conspiracy. In the United States only 36 percent of respondents disbelieved every theory proposed.

In the UK some of the more fringe conspiratorial views were, unsurprisingly, not widely believed. Only 10 percent thought the harmful truth of vaccines was being suppressed, eight percent believed contact with aliens was covered up, four percent thought AIDS was intentionally created and spread by humans, and just two percent denied the holocaust actually happened.

On more modern political issues, the results were a little more confronting. A much larger volume of respondents agreed with the conspiratorial idea that, "The government is deliberately hiding the truth about how many immigrants really live in this country." A stunning 48 percent of respondents in Hungary, a country currently run by a controversial prime minister known to provoke anti-immigrant sentiments, agreed with that statement. Germany was next with 35 percent agreement, and 21 percent agreement in the United States.

Drilling further down into this belief, the research revealed that individual political allegiances dramatically influenced how people approached this specific conspiracy, with 44 percent of Trump voters and 47 percent of Brexit voters agreeing that the government is covering up immigration levels. This compares to just 12 percent of Hillary Clinton voters and 14 percent of Remain voters.

"The conspiratorial perception that governments are deliberately hiding the truth about levels of migration appears to be backed by a considerable portion of the population across much of Europe and the United States," says Hugo Leal, a researcher working on the project.

Even more extreme was the study into a conspiracy theory known as "the great replacement." This idea suggests the increasing waves of Muslim immigration across Europe, and into the United States, is part of a grand plan to slowly turn Muslims into a majority in certain countries. While only three percent of Clinton voters and six percent of Remain voters agreed with this belief, a striking 41 percent of Trump voters and 31 percent of Brexit voters believed this to be true.

"Originally formulated in French far-right circles, the widespread belief in a supposedly outlandish nativist conspiracy theory known as the 'great replacement' is an important marker and predictor of the Trump and Brexit votes," says Leal.

Overall, the most generally believed conspiracy was the claim, "even though we live in what's called a democracy, a few people will always run things in this country anyway." On average 44 percent of agreed with this statement.

The study also polled levels of trust in different sources, and unsurprisingly around three-quarters of all subjects distrusted governments and big business. The "fake news" wave also proved strong, with journalists raking in high levels of distrust across all countries – an average of 77 percent of respondents reported distrust in journalism.

On the bright side, academics still seemed to retain significant trust from the general public with over half of respondents signaling they still highly trust those scientific and university perspectives. However, in general, the only people most respondents truly trusted were friends and family. Across all countries around 90 percent of the polled subjects reported high levels of trust in friends and family.

While this final data point undeniably affirms the dangerous nature of social media echo chambers, where conspiracy theorists mutually reinforce their beliefs with each other, it does suggest an opportunity for those close friends and family to help drag loved ones away from the precipice of fringe conspiratorial beliefs.

"So if you have a friend who starts sayings things about how the CIA was behind 9/11, try talking to them," suggests one of the researchers on the project Hugo Drochon, in an editorial for The Guardian. "You never know, they might come round to thinking it was al-Qaida who hijacked the planes, after all."