Contributed by Dr. Gleb Tsipursky, disaster avoidance expert, speaker and author. 

Whenever you hear something repeated, it feels more true when you hear it repeated. In other words, repetition makes any statement seem more true. So anything you hear will feel more true each time you hear it again.

Do you see what I did there? Each of the three sentences above conveyed the same message. Yet each time you read the next sentence, it felt more and more true. Cognitive neuroscientists like myself call this the “illusory truth effect.”

Go back and recall your experience reading the first sentence. It probably felt strange and disconcerting, perhaps with a tone of outrage, as in “I don’t believe things more if they’re repeated!”

Reading the second sentence did not inspire such a strong reaction. Your reaction to the third sentence was tame by comparison.

Why? Because of a phenomenon called “cognitive fluency,” meaning how easily we process information. Much of our vulnerability to deception in all areas of life—including misinformation—revolves around cognitive fluency in one way or another.