Research shows that having a few incompetent or disliked employees can affect the performance of all employees in a workplace. Destructive workplace behaviors can spread to other employees. While the focus tends to be on developing leaders and high performers, studies show it is important to reform bad workplace behaviors, or if that is not possible, to remove employees participating in those behaviors. One study found that one unproductive employee can decrease performance by more than 30%. Researchers say the best way to ensure productivity is to screen employees carefully, and to remove those employees who slip through the screening process.
See "How a Few Bad Apples Ruin Everything", Robert Sutton, The Wall Street Journal, October 30, 2011