The 9 Most Commonly Believed Conspiracy Theories

Scientists has widely dismissed Sasquatch as a mix of folklore, misidentification and hoaxes. After centuries of alleged sightings there would have to be a substantial number of bigfoots to maintain a breeding population, yet no one has ever found a dwelling/nest, droppings or a body, let alone manage to capture a living specimen.

One of the most famous pieces of Bigfoot evidence to ever exist is the Patterson–Gimlin film which was shot in 1967 and shows Sasquatch walking along Bluff Creek in California.

This video is famously known to be a hoax, even Robert Glimlin who shot the video said in a 1999 interview, "I was totally convinced no one could fool me. And of course I'm an older man now... and I think there could have been the possibility of a hoax. But it would have to be really well planned by Roger Patterson."

Despite the the lack of any evidence to back up its existence, 14% of Americans still believe that Bigfoot exists.

The 17 minute black and white film was sold to television networks and broadcast in more than 33 countries. It appeared to show the complete autopsy of an extraterrestrial being. Ray claimed that the footage was given to him by a retired military cameraman who wished to remain anonymous.

This was really the first big conspiracy theory to be born thanks to the internet. Theories about the US government's involvement in the events of Tuesday 11th September , 2001 have been debated over and over on countless forums.

The theories range from the belief that the Bush administration had prior knowledge of the attacks and didn't act upon it, to claims that the whole attack was orchestrated by the government.

Either way, Bush's reasoning was to gain more power and support his war on terror and the invasions of Afghanistan and Iraq.

It's been claimed that explosives were planted to bring down the World Trade Center towers, that a plane didn't crash into the Pentagon and it was in fact a missile, and that Flight 93 was shot down over Pennsylvania.

These outlandish claims have been proved false time and time again, popular mechanics magazine, Popular Mechanics investigated claims of a controlled demolition and say the towers fell as a result of the impact of the aircraft and the subsequent fires.

When a commercial flight from Kuala Lumpur to Beijing vanished without a trace on March 8th, 2014, conspiracy theorist were quick to speculate that there was more to this story than the media were reporting.

It seems that the fate of MH370 was predicted by rapper, Pitbull. In his song 'Get It Started' he sings the lyrics, "now it's off to Malaysia" and "two passports, three cities, two countries, one day."

Some believe that terrorists hijacked the plane and landed it somewhere to be used at a later date in a 9/11-style attack while other think the Boeing was landed on the more than adequate runway at the US military's base on the island Diego Garcia.

A freelance journalist claimed to have received a photo via text message from an MH370 passenger calling himself Phillip Wood. Data contained with in the black iPhone photo contained GPS information which placed Wood on the island. The internet was quick to quash these claims offering the more likely explanation that the photo is a fake. The question of whether the plane was landed on the island was asked in a White House press conference, press secretary Jay Carney simply answered "I'll rule that one out."

Many politicians and political parties are backed by wealthy individuals and corporations, perhaps these organisations are pulling the strings of governments around the world but assuming that these powerful people are part of a secret society is a step too far.

People have speculated over the existence of groups like The Illuminati for centuries. Clearly The Illuminati once existed, being formed in Bavaria in 1776, but very few really believe they still exist today.

The People's Princess was killed in a car crash in 1997 in an underpass in Paris while being pursued by paparazzi.

It didn't take long for theories to surface about a more sinister cause for Diana's death. Some speculated that she was pregnant and planning to marry Dodi Al-Fayed. It's said the palace didn't want her to bring a Muslim baby into the world so they had her killed.

A less extreme theory is that the Royal Family wanted her out of the picture so that people would support Prince Charles's second marriage. Some even say she faked her death to escape the public eye.

The crux of this theory is that, despite decades of research and proven findings by scientists from all around the world, global warming is entirely fabricated or not caused by human's presence on the planet.

It's hard to deny that average temperatures on Earth are rising year by year, but those who subscribe to this theory refuse to believe that climate change is a man-made issue.

Although scientific opinion on climate change is that human activity is the primary driver of climate change, the politics of global warming have been affected by climate change denial, slowing down efforts to prevent global warming.

Worryingly, 37% of Americans believe this conspiracy, including the US president himself.

JFK was shot in 1963 while riding in a presidential motorcade in Dallas. Within two hours, Lee Harvey Oswald was arrested for the murder of a police man, several hours later he was also charged with the presidential assassination.

Before Oswald could testify he was shot dead just two days later, this suspicious killing lead to the belief that he was incorrectly fingered for the killing, backed up by the fact that witnesses claim to have heard shots coming from the grassy knoll, indicating the existence of an unknown, second shooter.

In 1964, it was concluded by an official investigation that Lee Harvey Oswald was the only person responsible for assassinating Kennedy. However, in 1979, the United States House Select Committee on Assassinations said that a second gunman "probably" fired an extra bullet at Kennedy but didn't go as far as to identify the shooter.

But just because there was a second shooter doesn't mean that the CIA, Fidel Castro or the KGB were involved in the presidents death or a subsequent cover up.