The one question fantasists always slip out of…

There are plenty of unsubstantiated beliefs lurking among us, from alien invasions to a flat Earth, from a Jewish zombie to “enlightened” meditation, from ghosts to poltergeists, from mediums to prophets… and that’s not even mentioning all the conspiracy theories (Jews, Illuminati, Lizards, scientists, medicos, take your pick). Heck, you’ll often find a conspiracy theory mixed in with some other silly belief in the same individual.

One thing unites them all: whenever a believer is asked to provide the evidence and reasoning that should lead a rational person to agree with the believer… none is forthcoming. I mean… sure, you often get pathetic excuses or spurious reasoning… but you NEVER get sound reason.

Often it goes something like this:

Person A: I believe that aliens have set up a base here on Earth but they’re hiding from us.
Person B: Where is your evidence?
Person A: There’s no evidence, silly: the aliens are good at hiding.

Or, yes, even something like this:

Person A: I believe in God.
Person B: Where is your evidence?
Person A: God doesn’t have to live up to your demand for evidence. Besides, if He revealed Himself then you’d have no free will.

Here’s the question for debate:

Why is it that these people don’t recognize that believing something without evidence is a fool’s game? What, in other words, is the primary failing of human cognition that allows the prevalence of unsubstantiated beliefs?

Do you believe anything for which you cannot produce reasonable evidence? If so… WHY?