During Barack Obama’s campaign stop last week in Allentown, Pennsylvania, he scratched his head with his middle finger as he named the mayor of Bethlehem, John Callahan, a Hillary Clinton supporter. Right before the 2008 election, presidential candidate Barack Obama made a remark about his opponent, John McCain. As he made the remark, Obama scratched his face with his middle finger. Rush Limbaugh and others were quick to ask if Obama was giving the finger to Senator McCain. Dr. Anna Salter’s research on sexual predators gives us some clues as to why we are so often unable to spot a...