Between two people of equal talent, over-confidence may be the deciding factor in who will be more influential, even if it's pure self-deception, according to a recent study.

"These findings suggest that people don't always reward the most accomplished individual but rather the most self-deceived," says study author Dr. Vivek Nityananda, a research associate at Newcastle University. "We think this supports an evolutionary theory of self-deception."

Dr. Nityananda and colleagues worked with 72 students, asking them to assess their own abilities and the ability of their peers on the first day of their class and six weeks later once the students had gotten to know each other.

In the first comparative self-assessment, 32 students -- about 45 percent -- were under-confident in their ability, reflected by their final grades for the course. Twenty-nine -- about 40 percent -- were overconfident and only 11 students -- 15 percent -- were accurate in their assessments of their own abilities.

Students who predicted high grades for themselves were generally predicted to receive high grades by the others and the inverse was true, disregarding the final score.

"It can be beneficial to have others believe you are better than you are and the best way to do this is to deceive yourself, which might be what we have evolved to do," says Dr. Nityananda.

When the exercise was repeated towards the end of the course, findings were the same: Over-confidents were overrated.

The trouble with all this, say researchers, is that because we're only human, this type of self-determined hierarchy gets us in trouble.

On a small scale, though, the takeaway is obvious: Tell yourself you're great and the world will agree.

The study was published in PLOS ONE.