Have you ever heard of the syndrome known as Koro? I hadn’t until just recently:
The word is also used in Makassarese language, meaning “to shrink”; the full dialect for it is garring koro. In Malay, keruk is the probable linguistic link of koro which means “to shrink”. The term shuk yang, adapted from Chinese, means “the shrinkage of penis” – wikipedia
Apparently there’s a pretty common bit of human wiring that leaves us concerned that our assets are disappearing – this can lead to some pretty unpleasant self-conducted “medical treatment”.
Extremely anxious sufferers and their family members may resort to physical methods to prevent the believed retraction of the penis. A man may perform manual or mechanical penile traction, or “anchoring” by a loop of string or some clamping device. Similarly, a woman may be seen grabbing her own breast, pulling her nipple, or even having iron pins inserted into the nipple. Physical injury is inevitable, which can be considered as a complication of the syndrome. – wikipedia
Apparently its a very culturally bound problem – like spotting UFOs or attending Nickelback concerts – but, fortunately, proper treatment is pretty rational:
In historical culture-bound cases, reassurance and talks on sexual anatomy are given. Patients are treated with psychotherapy distributed according to symptoms and to etiologically significant points in the past. Prognosis appears to be better in cases with a previously functional personality, a short history and low frequency of attacks, and a relatively uncomplicated sexual life.
So, if anything, this seems like a great argument for health classes in public schools.