Managers concede that favoritism plays a big role in deciding who gets promoted, however few will admit to playing favorites.

According to a new report from Georgetown University's McDonough School of Business and research firm Penn Schoen Berland, the vast majority of business leaders say favoritism-defined in the survey as preferential treatment based on factors unrelated to a person's abilities, such as background, ideology or gut instincts-is a factor in how workers get promoted. The study was based on interviews with 303 senior business executives at U.S. companies with at least 1,000 employees. While 84% of those surveyed say favoritism takes place at their own organizations, just 23% acknowledged practicing it themselves, and 9% say it was a factor in determining their last promotion.

Even that 9% was higher than the report's author, Jonathan Gardner, had expected. 'No one at this level of executive was going to admit it blatantly,' he said. Mr. Gardner, chief operating officer at Penn Schoen Berland, conducted the study while completing an executive master's degree in leadership at McDonough.

Nearly three-quarters of the survey respondents said there are procedures in place to ensure fairness in promotion decisions, such as having multiple people interview a candidate, and they do use other criteria like assessing job-related skills and a history of strong performance reviews. But they also listed a number of more subjective criteria, including trustworthiness and comfort working with an employeeand whether the candidate 'fits' into the corporate culture. More telling: Executives often limit their searches to a single candidate or have a preferred candidate before the application process even begins.

Playing favorites might benefit the newly promoted employee, but it could cause stresselsewhere, said Lamar Reinsch, a management professor at McDonough and Mr. Gardner's adviser on the paper. Mr. Reinsch said it is particularly detrimental at top levels of management, as staffers question the person's creditability and question the promotion process at large. Productivity and morale can suffer. 'They're now playing office politics instead of focusing on organizational objectives,' he said.