Exactly. Polygraphs (and voice stress analysis, and fMRI, and any other so-called deception detecting technology) work because they frighten people into fessing up. THAT'S why police departments still use them. The science they are based upon is sketchy or misleading at best, and completely dismisses the inherent complexity of an act such as lying.

Except that (and this has been repeated time and time again above) -- it will NOT devour 'every bit of matter between the black hole and the center of the earth'. The chances of it hitting anything, even if it passes through the nucleus of an atom (which, relative to the size of the black hole, is largely empty space), is minuscule. The black hole would be so tiny, and its gravitational pull so slight, that the chances of it sweeping up any matter at all (let alone the entire planet) before it evaporated are not even worth bothering with.

Ah, the good old nature vs nurture debate.

There are a lot of behaviours not exhibited by babies and young children that are nonetheless not 'learned' behaviours (their brains are still developing, after all). Some behaviourists have insisted that facial expressions, and even emotions, are entirely learned, despite irrefutable evidence to the contrary. The prevalence of arachnophobia suggests that there could be an inborn tendency to develop it. This would not make it entirely unlearned (and does not mean that one could not be conditioned to overcome it), but to insist that it is an invention of western culture perpetuated by Hollywood is likely incorrect.

I have nothing against spiders. I appreciate what they do. I'm not bothered by jumping spiders (even the big ones) or daddy longlegs, or insects. But something about the way wolf spiders move, or the dangling legs of orb weavers, triggers a very powerful phobia in me, and this seems to be the quality that bothers others that I've discussed this with as well. I have family members that are afraid of snakes, or mice, or earwigs, and I never developed a phobia of any of these creatures. I'm not looking to excuse my phobia, but I hear alarm bells go off any time someone insists that a behaviour can't possibly have an inborn component.