The project manager is a key ingredient in the success of a project. In addition to providing leadership in planning, organizing, and controlling the project, the manager should possess a set of skills that will both inspire the project team to succeed and win the confidence of the customer. Effective project managers have strong leadership ability, the ability to develop people, excellent communication skills, good interpersonal skills, the ability to handle stress, problem-solving skills, and time management skills.
The PM needs to be able to create an environment that is comfortable. A comfortable environment is one that leads to innovation and productivity(2). In order to do this the PM must have certain human skills. It's these human skills that are either natural or learned. The ones that are innate, or natural, are the social skills. Often subsets of social skills, such as communication, negotiation, team building, are aspects that can be learned, but often times social skills are a subset of personality, which is something we are born with.
It is without a doubt that various personality types can make successful project managers. There is no doubt that both introverts and extroverts have made successful project managers in the past and will do so in the future. The argument here is that introverts will need to expend much greater energy developing their socials skills than extroverts will need to. Some of the social skills that have been documented as important for project managers are communication, negotiation, team building, and forming alliances. These skills will come more naturally for extroverts. However, the good news for introverts is that social skills are only part of the equation for developing successful program managers. Eventually, it is those individuals with problem solving abilities and the ability to get the job done will be most apt to succeed.