Forty years ago, on the morning of August 23, 1973, Jan Erik Olsson—a prisoner who was free thanks to a special permit—armed with an automatic pistol and explosives, headed to a Kreditbanken agency in Norrmalmstorg, in the center of the Swedish capital, Stockholm, with the intent to commit a robbery. However, upon crossing the bank’s threshold, things got complicated, forcing him to barricade himself inside and hold four people who were there at the time hostage.

The Swedish police acted quickly, arriving at the scene and immediately cordoning off the area with technical teams and snipers. Two officers entered the bank, leading to an exchange of gunfire. Olsson responded by shooting and injuring one officer, and took the hostages.

To begin negotiations, Olsson demanded the presence of Clark Olofsson, one of the country’s most notorious criminals, who was serving a sentence at the time and with whom Olsson had crossed paths in prison. He also demanded three million Swedish kronor, two revolvers, bulletproof vests, helmets, and a vehicle.

The authorities agreed to part of his demands and brought Olofsson to the bank, where another employee, who had been hiding, joined the group of hostages. This was the first criminal event broadcast live on Swedish television, where a robber, a prisoner, and four employees lived together for six days—the last four confined to a limited space after officers managed to infiltrate the bank and close the vault to isolate them.

Contrary to expectations, the hostages developed a relationship of complicity with their captors. They played cards, formed emotional and psychological bonds, and even defended their captors in the subsequent trial. To everyone’s surprise, Kristin Ehnmark, one of the hostages, not only expressed fear of a police action that could end in tragedy but also resisted the idea of a possible rescue. She said she felt safe.

After six days of captivity and threats from the captor, the police decided to act. Through the vault’s ceiling, they began to release tear gas, prompting Olsson’s surrender within minutes.

No one was injured. Both Olsson and Olofsson were convicted and sentenced, although the charges against Olofsson were later dropped, and he returned to a life of crime. Jan Olsson, on the other hand, after serving a 10-year sentence, was released from prison fully rehabilitated and with a large following of fans and supporters.

Throughout the entire judicial process, the hostages were reluctant to testify against those who had been their captors, and even today, they express feeling more frightened by the police than by the robbers who held them hostage for nearly a week. This series of events led to the naming of a psychological term now commonly used worldwide: “Stockholm Syndrome,” which refers to hostages who develop this type of attachment to their captors.

The Swedish psychiatrist and criminologist Nils Bejerot was the one who coined and introduced the term to describe this psychopathic phenomenon, which has never been characterized as a set of clinical signs and symptoms with its own diagnostic entity, nor even as a tentative descriptive and explanatory model.

Other researchers who have studied the topic suggest that it is an interpersonal protective bond developed between the victim and the aggressor in a traumatic and isolated environment, based on the induction in the victim of a mental model, cognitive in nature and contextually anchored, whose primary function would be to restore the physiological and behavioral homeostasis of the attacked individual and protect their psychological integrity. In other words, it seeks to rebalance the “attacked” person through this temporary adaptation disorder in the presence of massive interpersonal and environmental stressors.

Some authors believe that there are still gaps regarding this syndrome. However, they find enough similarities between studies of kidnapped hostage cases that could be used as the basis for diagnostic criteria.

The uniqueness of this syndrome lies in a pattern of cognitive changes, its adaptive functionality, and its terminal course as a result of the psychological changes produced in the victim in various phases, from the onset of the traumatic situation.

According to Bejerot, this syndrome is more common in people who have been victims of some other form of abuse, such as hostages, cult members, emotionally abused children, incest victims, or prisoners of war or concentration camps. Whatever the situation, the emotional bond with the abuser would, in fact, be a survival strategy for the hostages.

Stockholm Syndrome can also be found in family, romantic, interpersonal, and even work relationships because the abuser can be anyone in a position of control or authority.

The main characteristic of this emotional disorder is the moral justification and the feeling of gratitude from one person towards another on whom they depend—either forcibly or pathologically—for their real or imagined chances of survival.

Although it is still not possible to establish its etiology, what is clear is that this syndrome, with its long history, is more than an urban myth, in part due to the numerous high-profile cases that have sparked debate and exchange of opinions on a phenomenon that is fascinatingly difficult to understand.