A standard criticism of happy people is that they're not realistic—they sail through life blissfully unaware of the world's ills and problems. Satisfied people are less likely to be analytical and detail-oriented. A study led by University of New South Wales psychologist Joseph Forgas found that dispositionally happy people—those who have a general leaning toward the positive—are less skeptical than others. They tend to be uncritically open toward strangers and thus can be particularly gullible to lies and deceit. Think of the happy granny who is overcharged at the car dealership by the smiling salesperson compared with more discerning, slightly less upbeat consumers.