Few things are more painful to witness than extreme self-delusion. Think of the hopeless flirter being repeatedly rejected at a bar or the office bloviator going on and on about topics he doesn't understand while his co-workers roll their eyes. No one wants to be that person, and so self-delusion gets a seriously bad name. But perhaps we need to rethink our attitude towards those who overestimate their own abilities.

First off, because you're probably one of them.

That's according to Joseph T. Hallinan, the Pulitzer Prize-winning author of a new book entitled Kidding Ourselves: The Hidden Power of Self-Deception, who recently spoke to New York Magazine's Science of Us column about his investigations into self-deception.

Sure, of Course You're Above Average...

"There's a so-called 'overestimation bias' among men. It's pretty well-established among sex researchers--men generally think they're more attractive to women than women rate them," he says before adding that "there's also a bias in terms of IQ--everyone thinks they're smarter than the average person even though, of course, that can't always be true." We also, apparently, all tend to misremember our GPAs as higher than they actually were.

But rethinking self-deception isn't just necessary because we're more susceptible to this Lake Wobegon effect ("where all the children are above average") than we allow ourselves to believe, but also because overestimating our looks, charm and skill may not always be a bad thing. In it's extreme form, self-delusion is obviously a recipe for disaster, but its complete absence can be a hinderance in life. For instance, depressed people are actually more likely to have accurate self assessments, Hallinan notes.

While smashing your rose-tinted glasses can be terrible for your mood, putting them on can be great for your confidence. "Under the right conditions, if you're able to deceive yourself, it's what keeps you going," Hallinan says. "If when the going gets tough you're able to fool yourself into thinking things will work out, there can be an upside to this, and it's actually measurable, quantifiable, and can improve your performance in given situations."

Perseverance pays, in other words, and so does moderate over-confidence. "In situations where you're applying for colleges, jobs, or other situations where your smarts are on the line," Hallinan says, "it can help you... to believe that you're a bit smarter than you may actually be."

A Psychological Immune System

The bottom line is, if you're spending a lot of time agonizing over whether you've accurately assessed your abilities (hello, sufferers of Imposter Syndrome!), but the world is giving you no cues that you've passed into the territory of the dangerously deluded, it will probably pay to stop worrying.

"Self-deception is a psychological immune system," Hallinan concludes, "but instead of attacking germs like the body's immune system does, it helps us stave off things that cause us to be unsuccessful in life, like depression. We have a built-in way of looking at the world, rose-colored glasses, that ultimately is very helpful."