Confidence begets more confidence.

Yet another study, this one by Cameron Anderson and Sebastien Brion of Berkeley's Institute of Labor and Empowerment, confirmed what most of us know is true. Some people are promoted based on their confidence and not necessarily by their competence.

That loud voice and emphatic gesticulation? They work. Really well. 

And it's a feedback loop. Confident people get promoted, which makes them feel more confident, which makes them seem more confident.... 

Ironically, people who are actually competent have lower assessment of their skills (shown in other studies), so they don't exude the same level of confidence.

So the lesson is, be an airbag and be promoted. Just kidding. The lesson is, don't be taken in by the peacock strutting. The bird can't fly. And there's more to life than gaining positional power and wealth. 

See also related article, Faking your way to power.