What makes us believe a false claim? Age, education, and cognitive biases all play a part

28 February 2020 | DORA-OLIVIA VICOL

Have you heard the myth about spinach being an incredible source of iron? Or maybe you read somewhere that this was all a myth popularised by Popeye, the pipe-smoking sailor?

If you believe any of these claims, you are not alone. Countless websites, national broadcasters, and even textbooks made these claims very familiar. But they are also unfounded. Spinach is rich in iron, just not the type the human body absorbs well. For his part, Popeye loves Spinach for its Vitamin A content, not for the iron. Yet somehow, familiarity inspires belief.

The consequences of the spinach misconception are relatively harmless. But when a piece of untrue information has the potential to affect decisions about our health, our finances, or our vote - being aware of our belief biases can prevent real harm. This is why we wrote this briefing: to find out what shapes belief in misinformation, and help readers spot it.

Age and education

Studies have shown that age and education levels affect our ability to distinguish fact from opinion.

A survey by the Pew Research Centre conducted in the US found that adults over 50 and adults without college education find it harder to identify statements introducing factual information, from those which are merely opinion pieces. Across psychology research, a substantial body of literature finds that seniors experience difficulty in recalling details, even though they might remember the overall message of a story.

Beyond these demographic associations however, we all have certain biases we should be aware of.


As with the spinach myths, we are all prone to believing the things we hear over and over. Experiments have found that headlines seen repeatedly are more likely to be perceived as accurate, even when they hold no basis in reality, and even when participants cannot recall seeing them before.

Fluent content which is easy to process

Elements which influence the ease with which a statement can be read - such as font size, contrast, and the presence of pictures in particular - can also affect how much it appears true.

This is known as “processing fluency”, and it refers to the ease with which we can decode a piece of information.

Our existing worldviews

We also tend to believe the evidence that confirms our worldviews, and dispute that which challenges us.

Studies of long-debunked myths, such as climate scepticism, have found that participants who held strong hierarchical and individualistic views were more likely to reject the evidence, despite being highly educated and perfectly able to comprehend it.

Psychologists call this motivated reasoning. In some cases, we can mitigate this bias by reining in our “fast” reacting gut instinct, and taking the time to “think slow” - examining new evidence for what it says, rather than for how it conforms with what we already believe. A number of studies have found that this type of analytical thinking can cut through partisanship - though this is much easier to do in the case of novel claims, than in the case of entrenched myths.

Misinformation is something we can all fall prey to

It is important to realise that belief is a complex psycho-social process. Everyone is susceptible to believing things which are repeated, easy to process, and aligned with our worldviews. We get more distracted on social media than on other news media, and we tend to share information high in emotion.

Perhaps most notably, as readers we are not just passive recipients of misinformation.

Sometimes, we actively share and condone it

A survey of UK adults conducted in 2018 found that as many as 43% of users reported sharing problematic content – this included 25% who shared at least one news story which they thought was entirely made up or exaggerated, and 29% who shared a story which they later found was made up.

While one in two respondents surveyed reported spotting content which was inaccurate on social media, only one in five reported correcting those who share it.

What can we do?

As Full Fact’s readers, you can make a difference.

Sharing the fact checks you come across can play an important role in preventing bad information from spreading.

Why don’t you try it today?

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