This means they are often promoted over those who may be more competent than themselves, as their bosses mistake their confidence for real talent.

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Better-looking women are more likely to be hired and promoted than those who are less attractive.

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The company recently launched a new feature called Promoted Accounts, where companies can pay Twitter to be featured more prominently on the site to attract more followers.

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"We'll do what needs to be done, and more, " insists Mr Robertson, who was recently promoted to BMW's management board.

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But change the rules, make there be any question of the qualification of the person so promoted, however understandable the goal of more rapidly effecting that change, is immoral, in that you deprive the person of the fullness of their own legitimate achievement, in their own eyes and in the eyes of everyone looking at them.

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In addition to scoring worse on performance reviews, external hires were 61% more likely to be fired from their new jobs than were those who had been promoted from within the firm.

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And she worked hard, and she was good at what she did, but like so many women she hit that glass ceiling, and watched men no more qualified than she was -- men she had actually trained -- be promoted up that ladder ahead of her.

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As a board member on dozens of companies, the CEO of several firms, and an executive on many more, I have spent countless hours behind closed doors with fellow leaders discussing what employee should be promoted within the company.

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