Friday post: New ecosystem service--Tarantulas Help Scientists Break Down Human Fear

"The scientists also asked volunteers beforehand how scared they thought they might be of the tarantula, and found that those who thought they would be most scared had a false impression afterwards of how large the spider was.

The scientists think it may be this so-called "expectation error" that could be the key to people developing a phobia -- an irrational, intense and persistent fear of certain things, people, animals or situations (more)."