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.
Certainly having an eye for the finer points can be helpful when navigating the complicated social world of colleagues, acquaintances, and dates—and it's something the less sunny among us bring to bear. In fact, Virginia Commonwealth University psychologist Paul Andrews has argued that depression is actually adaptive. Depressed people, the logic goes, are more likely than others to reflect on and process their experiences—and thereby gain insight into themselves or the human condition—albeit at an emotional price. A little attention to detail helps with a more realistic evaluation of the social world.
Yet too much attention to detail can interfere with basic day-to-day functioning, as evidenced by research from Queen's University psychologist Kate Harkness, who found that people in a depressed mood were more likely to notice minute changes in facial expressions. Meanwhile, happy people tend to overlook such second-to-second alterations—a flash of annoyance, a sarcastic grin. You probably recognize this phenomenon from interactions you've had with your partner. While in a bad mood we tend to notice the tiniest shifts and often can't seem to disengage from a fight ("I saw you roll your eyes at me! Why did you do that!?!"), whereas when we're in a good mood, we tend to brush off tiny sleights ("You tease me, but I know you love being around me"). The happiest people have a natural emotional protection against getting sucked in by the intense gravitational pull of little details.
Similarly, the happiest people possess a devil-may-care attitude about performance. In a review of the research literature by Oishi and his colleagues, the happiest people—those who scored a 9 or 10 out of 10 on measures of life satisfaction—tended to perform less well than moderately happy people in accomplishments such as grades, class attendance, or work salaries. In short, they were less conscientious about their performance; to them, sacrificing some degree of achievement seems to be a small price to pay for not having to sweat the small stuff.
This is not to say that we should take a laissez-faire attitude to all our responsibilities; paying attention to detail is helpful. But too much focus on minutiae can be exhausting and paralyzing. The happiest among us (cheerfully) accept that striving for perfection—and a perfectly smooth interaction with everyone at all times—is a loser's bet.