Some red flags can help you identify a toxic person, according to the MIT Sloan School of Management. The first is narcissism, or an excessive interest in or admiration of one’s self.  Next is Machiavellianism, the power-hungry and unethical mindset made famous by Niccolo Machiavelli’s 16th century work “The Prince.” Last is psychopathy, an inability to deal appropriately with one’s negative emotions and impulses.  Click for article