Shmuel "Sam" Vaknin (born April 21, 1961) is an Israeli writer and professor of psychology. He is the author of Malignant Self Love: Narcissism Revisited (1999), was the last editor-in-chief of the now-defunct political news website Global Politician, and runs a private website about narcissistic personality disorder (NPD). He has also postulated a theory on chronons and time asymmetry.