Jealousy is that ugly little thing in your head that can give rise to negative emotions. You often tend to behave and act is a way that is not good. Researchers from the University of Delaware say that jealousy really is blinding. They found that women who were made to feel jealous were so distracted they could not spot targets in a computer test. They claim that their results reveal something profound about social relationships and perception: It has long been known that the emotions involved in social relationships affect mental and physical health but now it appears that social