One set of knuckles meets another. Both are equal in this greeting that expresses approval and triumph. Meredith Rizzo/NPR hide caption itoggle caption Meredith Rizzo/NPR Goats and Soda In The World Of Global Gestures, The Fist Bump Stands Alone July 19, 2014 Obama does it. And increasingly, so do folks around the world. Why is the fist bump so popular? And do other cultures have similar gestures?