My reaction isn't nearly so strong. If the spider is in an innocuous place and doesn't look jumpy then my first inclination is to look away and pretend it's not there. But I try to force myself to sit there and stare at it for a while, and scream out "SPIDER! There is a SPIDER! Spider. Spider." in my mind, or half-shout out it if I'm sure no one is around, to train myself to not flinch away from things that are unpleasant, and to keep my mind from getting into the habit of thinking that if I ignore something it will go away.
Okay, so for several years, I've been doing a fairly good job of excising out most of my irrational beliefs and fears.
The one that remains, however, is my fear of bugs and spiders. I'll SCREAM if I see one, dead or alive. And if there's one in my food, then I'm going to throw the entire plate out.
Is it common for LWers to have irrational reactions to bugs and spiders?
I know that there is "desensitization therapy", as highlighted by a Scientific American Frontiers episode a decade ago (where gradual exposure to the stimulus - a spider) - can desensitize a person with arachnophobia over time. But this can really only happen in controlled settings. In uncontrolled settings, such interaction can give you nightmares.