Steven Pinker says our perception of how violent we are as a species is skewed. Robert Leslie/TED hide caption

itoggle caption Robert Leslie/TED

Kansas center Jeff Withey (left) and Kentucky guard Darius Miller battle under the boards during the second half of the NCAA championship on April 2, 2012. Mark Humphrey/AP hide caption

itoggle caption Mark Humphrey/AP

"Beauty is not just for the imagination. It's actually a way of altering human behavior for the better." — Bill Strickland TED hide caption

itoggle caption TED