Amazing Nature: The Scrotum

Maybe it’s the topics he picks, but I always end up reading Jesse Bering’s column in SciAm. I don’t know if it was the subject matter or that I occasionally revert to an 8 year old, but his most recent article is as hilarious as it is informative. The crux:

Fortunately, human scrota don’t just hang there holding our testicles and brewing our sperm, they also “actively” employ some interesting thermoregulatory tactics to protect and promote males’ genetic interests. I place “actively” in scare quotes, of course, because although it would be rather odd to ascribe consciousness to human scrota, testicles do respond unintentionally to the reflexive actions of the cremasteric muscle. This muscle serves to retract the testicles so they are drawn up closer to the body when it gets too cold–just think cold shower–and also to relax them when it gets too hot. This up-and-down action happens on a moment-to-moment basis, thus male bodies continually optimize the gonadal climate for spermatogenesis and sperm storage. It’s also why it’s generally inadvisable for men to wear tight-fitting jeans or especially snug “tighty whities”–under these restrictive conditions the testicles are shoved up against the body and artificially warmed so that the cremasteric muscle cannot do its job properly. Another reason not to wear these things is that it’s no longer 1988.

[SciAm: Why Do Human Testicles Hang Like That?]