Credulousness obviously has it’s place in the keep-your-caveman-from-dying arena, but even then it only goes so far. If we have, for example, a dishonest caveman mommy who tells her son that the caveman devil will at you if you leave the cave at all, that kid’s not going to grow up to reproduce with his own species if he takes what mom says as a fact and never leaves the cave. At some point, evidence surpasses credulity, at least in practical matters.

From the point of the credulous though, you’re dead wrong about the tigers. There may be an absence of tigers, but there is the (imaginary) eternal damnation if we choose to be skeptical. Or the (imaginary) risk of causing your child to have autism if you vaccinate him.