"The Price family's history suggests that there might be some sort of "paranormal" ability that helps a person detect cryptids, and that this ability is at least partially genetic. On the other pseudopod, it could all be nothing more than empirical knowledge, handed down from one generation to the next with a bit more intensity than Great-Grandmother's kugelhupf recipe."
I'm sort of cheating with this one, because it's not really a question. At the same time, a lot of the questions I've received have been very narrow ("What's Istas's favorite kind of pie?"), and hence qualify as both a) spoilers and b) not very interesting to take apart in detail. So please, submit more questions, and I'll take a moment to ramble about the Price family. For funsies.
There is no paranormal ability that allows people to detect cryptids. Well, that's maybe not entirely true: Sarah, who is a telepath, can probably find other cryptids by reading their minds, and Artie, who is an empath, can point out people who are unduly nervous or unhappy, and Istas can smell the difference between many species (but does not consider having a bloodhound-level sense of smell to be a "paranormal ability," as she was born that way). But for the most part, it's observation, education, and knowing what to look for. The Prices are raised on a steady diet of "And how do we spot a bogeyman?" They take field trips to the local gorgon and harpy communities. They learn early how to spot the "probably not a human" signs, and also how to trick people into identifying their species, even if they can't quite tell what it is. It's science. Behavioral science, field biology, and deduction.
There's also an element of luck, which is where the rumors come in, at least in certain circles. "Healy luck: sometimes it's good, sometimes it's bad, but it's always interesting" used to be a fairly common saying within the family. No one knows for sure what kind of stock Fran came from, and it's possible that she has jink or leprechaun in her family tree, somewhere. Ditto for the Davies family, which joined the Covenant in the 1700s, a period when many "close enough to pass" cryptids made a bid at hiding in plain sight by signing up with their dearest enemy. So it's entirely possible that luck-manipulator genes have entered the family tree at one or more points. (Whether this has actually happened is something that I'm not saying.) But this is only luck: even if it's a factor, all it's going to do is put people who have it in the path of more cryptids, giving them more opportunities to exercise the deductive skills listed above.
Field biology is a matter of knowing what to look for, knowing where to look, and not giving up. The Prices have these qualities in spades.