The psychiatrist Ernest Hartmann (1934–) is well known for his research on nightmares. His father, Heinz Hartmann, was also a psychiatrist and studied under Sigmund Freud. The senior Hartmann is sometimes referred to as “the son of Freud.” Ernest Hartmann directs the sleep laboratory at Lemuel Shalluck Hospital in Boston, Massachusetts. He also teaches at Tufts University.
One of the first studies that Hartmann conducted consisted of thirty-eight adults who suffered at least one nightmare a week for six months or longer. Most had been plagued by chronic nightmares since childhood. Each subject went through an extensive interview process in which his or her nightmare history, as well as the general content of the nightmares, was thoroughly documented. Eleven subjects from the original group were observed in sleep laboratories for a period of four nights. Hartmann was not satisfied with the results of this approach because he felt that the synthetic environment of the sleep laboratories affected the subjects and their dreams, which effectively tainted the data.
A second study group was comprised of three subgroups. The first consisted of individuals who suffered from frequent, lifelong nightmares. Members of the second group reported having vivid dreams but no significantly recurring or terrifying nightmares. The third group could not recall their dreams at all. Psychological tests and in-depth interviews were conducted and the content of the subjects’ dreams were examined. After the experiment concluded, Hartmann was able to establish that, while the subjects of the nightmare group did not share an inordinate number of traits with the members of the second or third groups, they did greatly resemble the personality profiles of the members of the original study. All of the nightmare sufferers had jobs that involved the arts (such as musicians or painters), or they were teachers, and none of them fit within society’s standard gender roles.
Hartmann went on to develop his theories concerning the “boundaries” of the mind, based on the information provided by these two studies. The development of a person’s boundaries is intricately related to the development of mental structures and faculties that begins early in a person’s life. These faculties distinguish between opposites, such as between self and others, inside and out, and fantasy and reality. Those who suffered from chronic nightmares were categorized as having “thin boundaries,” and shared characteristics of unusual openness, vulnerability, and difficulties with certain ego functions. These thin boundaries make individuals more aware of their inner feelings and the feelings of those around them, and make them more inclined to artistic pursuits. It also makes them painfully sensitive, not only to the threats of the outside world, but also to their own wishes and impulses. People with “thick boundaries” have stronger defenses to the outside world and to their own unconscious fears and impulses.