Before we start getting to smug about our sense of free will, let me just point out that there are widespread human brain parasites. One example is Toxoplama G

Before we start getting to smug about our sense of free will, let me just point out that there are widespread human brain parasites. One example is Toxoplama Gondii, which infects roughly 1/3 of the world's population. Studies have shown relationships between everything from increased car accidents to Bipolar disorder. Some have even suggested its distribution across regions affects human culture. http://discovermagazine.com/2007/feb/toxoplasma-gondii-culture-sex-ratio http://discovermagazine.com/2007/feb/toxoplasma-gondii-cultu...