The “illusion of truth”

When your mind comes across “information”, it has to judge if this information is true or false.

Unfortunately, your mind can be quite “lazy” when it has to analyse information. It “prefers” to analyse information it has seen before, as analysing such information needs much less effort than that needed to analyse new information, which it has not seen before. This can make your mind have the tendency to lazily believe that information it has seen before to be “true” whereas new information it has not seen before to be “false”. Of course, in reality, this makes no sense, because whether information is true or false has nothing to do with whether the information has been seen before or not. This tendency for one’s mind to mistakenly consider information it has seen before to be true, is called by psychologists, the “illusion of truth” mistake.

Below is an example of how the “illusion of truth” mistake made by one’s mind can be harmful.


You are probably aware that “fake news” has become a big problem in our world. This example will show you how the illusion of truth mistake plays an important role in “fake news”.

Imagine that someone, as a joke, makes an online video clip showing that because bananas are yellow, that they are bad for your health. In this video, the person mentions fake studies to support his theory. Of course, the information in the video is not at all true.

Now imagine that a person, who we will call Mary, sees the banana video clip. Also imagine that around the same time Mary sees the video clip, that many of her family members and friends also see the same video clip in their own homes. Over the next few days, when Mary meets her family and friends, she repeatedly hears from them about their opinion of the video clip. All of them repeat the message of the video clip, saying that yellow bananas are bad for one’s health.

As Mary repeatedly keeps hearing that yellow bananas are bad, her mind makes the illusion of truth mistake and makes her think, “I have heard it many times before that yellow bananas are bad, so this information must be true”. Soon this thinking makes Mary stop buying bananas, unnecessarily depriving herself of a fruit she used to enjoy.


Politicians, advertising agencies, and fake news outlets will all try to use your mind’s tendency to make the illusion of truth mistake to convince you that what they are saying is true. So when you see information that is repeated everywhere, don’t just assume that it is true. Do some basic research and enquiries before you make that judgment.