Protecting and maximising the quality of human interactions should be a high priority for LeaderShip and corporate culture. Under the heading of "The High-Tech Illusion", DeMarco writes in the first chapter of PeopleWare that "Because we go about this work in teams and projects and other tightly knit working groups, we are mostly in the human communications business. Our successes stem from good human interactions by all participants in the effort, and our failures stem from poor human interactions. ... Human interactions are complicated and never very crisp in their effects, but they matter more than any other aspect of the work." One of the reasons why human interactions are complicated is because they are affected by the psychology of their participants. There are a number of psychological models that might help us to understand these effects, for example the MyersBriggs model of sixteen different personality types. TransactionalAnalysis, as described in the book ImOkYoureOk, provides a particularly compelling and useful conceptual model for understanding the dynamics of human interactions. Interactions between leaders and followers, or between managers and employees, are particularly important. RogerSmith writes in EducatingManagers that "... [T]he attributes of excellence all depend on communications skills and sensitivity to people." Renn Zaphiropoulos, the founder of Versatec, is quoted in OnBecomingaLeader (p.87) as saying "It's vital to possess an adequate understanding of the first principles of human behavior in order to perform as optimum supervisors and directors of people.