From Psychologist Art Markman, Ph.D.'s HuffPost blog, IPA Research Affiliate Eldar Shafir's research is highlighted in showing how a positive or negative outlook can impact one's life.
When you are focused on the negative side of things, you often focus on rejecting options rather than selecting them. Witness what is happening with the GOP primaries now. Republican voters are focused on eliminating candidates rather than finding ones they like. Research by Eldar Shafir shows that when people are trying to reject options, they weigh the negative information about the options more heavily than the positive information.