Besides engaging in different personalities, another aspect of the extreme behavioral variance in this disorder is that of amnesia, or an inability to remember beyond what is considered average (American Psychiatric Association, 1994). In other words, besides extreme variability in behavior and self-report of identity, the self-reports of experiences the person has had also varies widely (Coons, 1994). When exhibiting some personalities, the person reports a history of abuse but not necessarily all the present circumstances. When another behavioral repertoire is exhibited, past abuse may not be reported but the present is reported clearly. It is this behavior that intrigues many. Clinicians and the lay public alike seem to want to know "Is it all in there?" That is, are all the memories and experiences stored somewhere in the mind or brain of this person?
From the behavior analytic point of view, remembering (or failing to remember) is a behavior, more or less likely to occur as a function of its antecedents and consequences (Grant, 1982; Grant & Barnet, 1991; Phelps & Cheney, 1996; Skinner, 1974); storage and accessibility are replaced with probability of remembering. With that clarified, one could say that some or most real experiences can be remembered (potentially) and reported; to remember we must arrange the environment to increase the probability that we will behave in the future as we are now behaving (Phelps & Cheney; Skinner, 1989). But in the cases of individuals with the behaviors of DID, the person is reluctant or unable to remember or report some experiences until that person is in a different situation or the reinforcement contingencies change. Then, the person may change personality repertoires and can remember and report different experiences. The vivid and lucid imagery of the past that is reported by these persons when displaying differential personalities corresponds with Skinner's "conditioned seeing" (Skinner, 1953). A person may come to see stimulus Z, not just when Z is in fact present, but also when other stimuli that have frequently accompanied Z are present. That is, if I can remember and reinstate the emotional behaviors of my past, I can come to see and hear aspects of my past. If I do not remember how I felt in the past, I am less likely to see, hear or otherwise re-experience the past again (Phelps, 2000). Hallucinations in our remembering like other hallucinations are highly context dependent (Hobson, 1994).
This differential remembering/reporting is also on a continuum in degree, not in kind, from the average person's behavior. We all remember, or fail to remember, as a function of discriminative stimuli. These discriminative stimuli, some of which are self-generated in our verbal behavior, and the reinforcement and punishment contingencies in effect at a given time, enable our remembering behavior. Environmental stimuli guide or prompt remembering just as stimuli guide or facilitate other behaviors (Donahoe & Palmer, 1994; Grant, 1982; Grant & Barnet, 1991; Phelps & Cheney, 1996; Skinner, 1974). But these individuals show behavioral variance in remembering and personality in response to highly specific and subtle stimuli, probably more in response to covert behaviors called moods, thoughts, etc., than the average person. This difference in controlling factors of these persons' verbal behavior is the key to conceptualizing these behaviors (Kohlenberg & Tsai, 1991; Phelps, 2000).