Many people claim to have only a single personality, which is ridiculous. Multiple personalities are readily apparent in others, although we sometimes regard this as pathological if we don’t like them. The problem is in the common habit of thinking about personality as tangible and definite, which it certainly is not. Personality is simply a set of inclinations toward a list of emotions or behaviors during a particular period of time. The list is defined by the observer and so is the period of time over which it is considered. Psychologists usually take the term of a personality to be an entire lifetime, and they tend to characterize personality in terms of the factors associated with their own dissertation. Laymen do likewise, but without the dissertation. Fluctuations and alternations in personality are therefore commonly regarded as mental illness, which they are generally not.

     The official DSM-IV definition of what used to be called Multiple Personality Disorder includes the following criteria:

1. The presence of two or more distinct identities or personality states, each with its own relatively enduring pattern of perceiving, relating to, and thinking about the environment and self. 

2. At least two of these identities or personality states recurrently take control of the person's behavior. 

3. Inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness. 

     Although I do not yet exhibit criterion C, I clearly do have multiple personalities. I have even claimed criterion C when called on the carpet for something particularly knuckleheaded. That’s my story and I’m stickin’ to it! Some of my personalities are optimistic, enthusiastic and vigorous while others are pessimistic, despondent and sluggish. Some are thoughtful and considerate while others are rash and insensitive. Some are rational and some are emotional. Some have good judgment and others do not, and they recurrently take control of my behavior.

     Like the various personalities in any organization, the ones in our heads require management. Several of my own personalities are no longer permitted to send email, although I rely upon some of these for my creative process. It is not possible to establish effective policies until you recognize your staff as a group of diverse individuals and get to know their strengths and weaknesses. You should designate one of your personalities to be CEO, and you should choose that one carefully.