Young, Jeffrey E.; Klosko, Janet S.; Weishaar, Marjorie E. (2006-11-03). Schema Therapy: A Practitioner's Guide (p. 4). Guilford Publications.Because characterological patients usually lack psychological flexibility, they are much less responsive to cognitive-behavioral techniques and frequently do not make meaningful changes in a short period of time. Rather, they are psychologically rigid. Rigidity is a hallmark of personality disorders (American Psychiatric Association, 1994, p. 633). These patients tend to express hopelessness about changing. Their characterological problems are ego-syntonic: Their self-destructive patterns seem to be so much a part of who they are that they cannot imagine altering them. Their problems are central to their sense of identity, and to give them up can seem like a form of death—a death of a part of the self. When challenged, these patients rigidly, reflexively, and sometimes aggressively cling to what they already believe to be true about themselves and the world.