Ego-syntonic refers to instincts or ideas that are acceptable to the self; that are compatible with one's values and ways of thinking. They are consistent with one's fundamental personality and beliefs. Ego-dystonic refers to thoughts, impulses, and behaviors that are felt to be repugnant, distressing, unacceptable or inconsistent with one's self-concept.
For a person who is a thief, stealing would be considered ego-syntonic, meaning that it comes naturally, there is unlikely to be any conflict about the act of stealing, and there is little or no guilt, as a result. For most people, stealing would be ego-dystonic, which is probably why we don’t do it. And, if we did, we would suffer greatly.
One client, a rather proper and respectful gentleman, began suspecting his wife of having an affair after her frequent explanations for evening absences seemed untruthful. One evening, he decided to check her e-mails while she was out and saw evidence that validated his suspicions. He arrived at his therapy session completely devastated; not by the discovery of his wife's infidelity, but by the fact that he found this out by doing something that "violated my code of ethics and moral standards." Remarkable as it may seem, his own ego-dystonic behavior – invading his wife's privacy by checking her e-mails behind her back – was actually more disturbing to him than the shocking discovery of his wife's betrayal. His emphasis was on figuring out how to best apologize for his transgression and less on how to handle hers.
One of the problems in working with certain psychiatric disorders in a therapeutic setting is the extent to which the disorder is experienced by the client as ego-syntonic or ego-dystonic. Mental health and medical professionals who work with certain eating disorders encounter the problem of patients who believe that their eating behavior is perfectly normal, i.e. ego-syntonic. Anorexia Nervosa is just such an example. This is an eating disorder which is characterized by extremely low body weight and body image distortion with an obsessive fear of gaining weight. People who suffer from this condition typically have poor insight and often refuse to accept that their weight is dangerously low even when it could be deadly. In other words, for the person suffering from this condition, their body and their eating behavior is "normal," or ego-syntonic in that they feel that there is nothing the matter with how they eat and live.
The task for the professionals involved in treating this disorder is, essentially, to make something that is ego-syntonic for the patient, something that is ego-dystonic, instead, so that there might be some leverage in bringing about meaningful and necessary emotional, physical, and behavioral change.
Another mental condition that is commonly known is obsessive-compulsive disorder. Obsessions are defined as recurrent and persistent thoughts, impulses, or images that are experienced as intrusive and inappropriate and that cause significant anxiety or distress. Compulsions are repetitive behaviors or mental acts that the person feels driven to perform in response, perhaps, to an obsession. Obsessive-compulsive disorder is thought of as an ego-dystonic disorder since, unlike anorexia nervosa, the person suffering is fully aware that there is something very much the matter with excessive worrying, for example, that are not about real-life problems. Similarly, the obsessive compulsive person knows that something is the matter with repetitive hand-washing or excessively checking to make sure that the door is locked, the oven is turned off, or similar behaviors. Despite the strength and persistence of these symptoms, therapy may yield better results since the person suffering recognizes that these symptoms are excessive and unreasonable, i.e. ego-dystonic, and, therefore, he or she may be more able to be actively engaged in the process of change.