A new study finds that, in 42% of companies, low performers actually report being more engaged - more motivated and more likely to enjoy working at their organization, for example - than middle and high performers do.

The findings suggest many organizations are not holding employees accountable for their work, allowing the worst workers to skate by, says Mark Murphy, CEO of Leadership IQ, the Atlanta-based consulting firm that conducted the survey.

"Low performers often end up with the easiest jobs because managers don't ask much of them," he said, so they're under less stress and they're more satisfied with their daily work lives.

Meanwhile, dedicated and conscientious workers end up staying at the office late, correcting the work of the low performers, and making sure clients or customers are satisfied.