Electric Shocks & Barbed Wire: The Psychology of Extreme Races Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Participants go through the Kiss of Mud obstacle at the Tough Mudder event at Raceway Park on October 21, 2012 in Englishtown, New Jersey. ( Bruce Bennett / Getty ) Produced by Amber Hall Produced by PRI and WNYC