I am looking for a word for (the act of) someone accepting information as fact without ever checking.
For example, I read an article in newspaper and believe it without fact checking. I tell my daughter about the article and my belief, she in turn tells her son and he believes too. Now 3 people believe and none have checked.
Best Answer
"the act of" in your question means you are looking for a noun. "gullibility" is one-word and seems to fit.
"credulity" also fits. (noun - readiness or willingness to believe especially on slight or uncertain evidence - Merriam-Webster)