http://www.scientificamerican.com/article.cfm?id=why-do-human-testicles-hang-…
Join over 320,000 readers. Get a free weekly update via email here.
Related posts:
New Neuroscience Reveals 4 Rituals That Will Make You Happy
New Harvard Research Reveals A Fun Way To Be More Successful
How To Get People To Like You: 7 Ways From An FBI Behavior Expert