An essential component of the Six Sigma approach to business improvement, is the training of employees for the role of process improvement specialist. These people usually have the words 'Black Belt' in their job title. Their role varies from company to company, but it invariably involves extensive use of statistical techniques. We suggest that some of the time devoted to statistics training could usefully be spent considering the human dynamics of improvement projects. More specifically we explore the benefits for Black Belts of understanding personality types. Copyright (C) 2004 John Wiley Sons, Ltd.