Airplanes and aliens: the truth about 9/11

Plane truth: Some claim that the vertical collapse of the towers is proof of foul play.

The 9/11 attacks are among the most well-documented events in history. Yet a vocal minority insists that they are one big lie. What do these conspiracy theorists believe instead? And why?

On September 11th 2001, three planes crashed into the World Trade Center and the Pentagon, killing 2,996 people. That is a fact. And the attacks were staged by shape-shifting lizards. That too is a fact – if you believe certain 9/11 ‘truthers’.

Fifteen years on, conspiracy theories about what happened that day are thriving. The spread of the internet has given them an ideal habitat. The theories differ over the culprit: aliens, Israel, the US government itself. But they agree on one point: the official line – that al-Qaeda did it – is a lie.

A conspiracy theory is the belief that a powerful organisation is secretly influencing events, usually for evil purposes. Some are reasonable; some even turn out to be true. Yet most are based on cherry-picked facts, and ignore overwhelming evidence to the contrary.

For example, some truthers insist that the World Trade Center was brought down by bombs planted by the US government, seeking an excuse to go to war with Iraq. They point to the ‘suspiciously neat’ collapse of the towers – which fell almost vertically – as proof of a controlled explosion. If structural engineers or eyewitnesses contradict them, they are denounced as part of the conspiracy.

Truthers are often ridiculed for their beliefs. Yet conspiracy theories endure, and not just on the fringes of society. Mainstream politicians propagate them – take Donald Trump’s insistence that President Obama faked his birth certificate. Celebrities regularly endorse them. According to one poll, 63% of American registered voters believe in at least one of them.

Why? Academics have long probed this question. They link conspiracy theories to various psychological phenomena, from confirmation bias – the tendency to look only at evidence that fits our existing beliefs – to pareidolia, whereby we perceive patterns where none exist. Socio-economic factors also seem to be at play; and mental health.

Yet the science on this subject is far from settled. Just like the truthers themselves, the experts do not always agree…

Before the facts

Conspiracy theories are more than just beliefs about specific events, argue some. They are an expression of a worldview. People resort to them to communicate their cynicism, their anger at an elite whom they view as malicious. This overarching ‘truth’, rather than the nitty-gritty of supporting evidence, is what matters to them the most.

It goes deeper than that, others insist. We have a primal instinct to look for order and design in chaos. Unpredictable events, such as terrorist attacks, confound and unnerve us. By explaining them in terms of a logical (if evil) conspiracy, these theories appeal to the rational side in us. They comfort us.

You Decide

  1. Is it wrong to mock conspiracy theorists?
  2. Is 9/11 the most significant event of the 21st century so far?


  1. How much evidence would a conspiracy theory need behind it before you accepted it as true? Discuss as a class, and come up with a list of basic principles.
  2. Pick a conspiracy theory that has proved particularly popular. Write an 800-word essay on why you think it has endured.

Some People Say...

“Conspiracy theories are very attractive.”

Neil Armstrong

What do you think?

Q & A

9/11 is old news. Why should I care?
It’s fair to say that the events of that day have shaped today’s world. They triggered an overhaul of security measures at airports. They paved the way for the West’s ‘War on Terror’. This has had huge implications for the stability of the Middle East, the threat of terrorism globally, and Western governments’ surveillance powers.
Why would the US government be behind 9/11?
For many of the above reasons, say conspiracy theorists. George Bush’s administration wanted a pretext to invade Iraq, to spy on its own people, or even to collect the insurance payout from the damage. In their view, it was willing to sacrifice thousands of its citizens to achieve this.
Err… shape-shifting lizards?!
This is a reference to the ‘reptilian’ theory. See Become An Expert.

Word Watch

Conspiracy theorists. The documentary series Loose Change is a famous example of the 9/11 ‘truth’ movement. It has been widely criticised for its inaccuracies.
The internet might help spread conspiracy theories in a variety of ways. First, it exposes them to a wide audience. Second, it provides a vast database of information from which theorists can cherry-pick ‘evidence’. Third, it is a hotbed for the sort of tribalism that underlies such theories.
An example: between 1932 and 1972, the US government was often alleged to be deliberately infecting black men with syphilis in order to study the disease’s behaviour. The government eventually revealed this was the case, and apologised.
Birth certificate
The so-called birthers, including Trump, alleged that Obama was not born in the USA and was therefore not eligible to run for president. Obama debunked the theory by publishing his birth certificate (see Become An Expert).
Conducted in 2013 byam Fairleigh Dickinson University.
Socio-economic factors
See the Scientific American article in Become An Expert.