Four percent of males and 0.5 percent of females exhibit the personality disorder called psychopathy-sociopathy: These are pathological liars devoid of conscience and ruthless manipulators. Even more chilling, psychopaths often present charming and charismatic demeanors. Jon Ronson, author of The Psychopath Test, will be at the Commonwealth Club to discuss exactly why you should watch out for that seemingly perfect OkCupid match you finally met. Ronson offers up his theories and tests with a lot of humor, exploring the idea that many corporate and governmental leaders are psychopaths. He's run some tests, and you can too! Ronson used the Robert D. Hare痴Psychopathy Checklist, a 20-part test administered to detect secret psychos with traits like "failure to accept responsibility for actions," "lack of realistic long-term goals," and "promiscuous sexual behavior!" Sounds like many twentysomethings out there. Don't be fooled.