Before the water pump fellows told their blister spider stories, no one standing around the wellhead would have said that in our area it's possible for a spider to exist capable of splattering blister-causing venom onto people's arms and faces, else we would have heard of it by now. Moreover, they'd have agreed that common sense says that such a small spider as the one on the water tank couldn't possibly expel such large amounts of venom over such long distances.

Yet, the blister spider stories were believed. Even the story about the black-and-white, fuzzy spider that delivers electrical jolts left everyone wide-eyed, at least at first.

Maybe our gullibility for such stories was hardwired into us, in our genes. Children believe most anything told to them by adults, and you can see how this would be adaptive for our species, and normally desirable. We all know that sometimes adults need a break from acting like adults all the time, so, at the wellhead, believing in blister spiders was like learning about the Tooth Fairy.

Since normally people don't like to be ignorant about the world around them, in general humans are predisposed to enjoy learning new things -- even if the learning comes from a doubtful source. Scott Lilienfeld, assistant professor of psychology at Emory University, says that "We have an adaptive reflex to make sense of the world... We need this ability, because the world is such a complex and chaotic place... "

Moreover, even if what we learn comes from a shady source, sometimes we use mind tricks to help us keep believing what we want to believe. Tory Higgins, chair of the psychology department at Columbia, says, "Once you have a belief, the way you look at evidence changes. When you search your memory, you are more likely to retrieve information that will support it and avoid exposure to information that will disconfirm it."

So, several guys standing around a wellhead were naturally disposed to believe stories about blister spiders and spiders that produced electrical jolts. There's an innocence about it that's almost touching. Yet, there's also danger in this kind of thing.

For, now that it's clear that we humans can destroy Life on Earth, it's fair to ask whether we still have the luxury of being so gullible about things others tell us. For the first time in human history we realize that we're living on a tiny, isolated and fragile planet suspended in an awful expanse of hostile space, so do we keep living our individual lives like always, doing what everyone else is doing, doing what everyone else says we need to do?

It seems like the smart thing for each of us to do is to reassess what we eat, where we set the thermostat, how far from work we live, etc. in terms of whether they're sustainable or not. And this rethinking process should not admit wishful thinking or fantasies of any given political faction, religion or fad belief.

The world is thick with folks talking about blister spiders and the like. To save Life on Earth we listeners have to keep in mind our own naturally gullible natures, turn away from the story tellers, and act instead on what we see with our own eyes, understand with our own minds, and feel deep within ourselves.