Stockholm syndrome is a condition in which hostages develop a psychological alliance with their captors during captivity. Emotional bonds may be formed between captors and captives, during intimate time together, but these are generally considered irrational in light of the danger or risk endured by the victims.
Stockholm syndrome has never been included in the Diagnostic and Statistical Manual of Mental Disorders or DSM, the standard tool for diagnostic of psychiatric illnesses and disorders, mainly due to the lack of a consistent body of academic research.
The syndrome is extremely rare as noted by the U.S. Federal Bureau of Investigation's Hostage Barricade Database System and Law Enforcement Bulletin estimating that fewer than 5% of kidnapping victims show evidence of Stockholm syndrome.
This term was first used by the media in 1973 when four hostages were taken during a bank robbery in Stockholm, Sweden. The hostages defended their captors after being released and would not agree to testify in court against them.
It was noted that in this case, however, the police were perceived to have acted with little care for the hostages' safety, providing an alternative reason for their unwillingness to testify. Stockholm syndrome is paradoxical because the sympathetic sentiments that captives feel towards their captors are the opposite of the fear and disdain which an onlooker might feel towards the captors.
There are four key components that characterize Stockholm syndrome:
A hostage's development of positive feelings towards the captor
No previous relationship between hostage and captor
A refusal by hostages to cooperate with police forces and other government authorities (unless the captors themselves happen to be members of police forces or government authorities).
A hostage's belief in the humanity of the captor because they cease to perceive the captor as a threat when the victim holds the same values as the aggressor.
Stockholm syndrome is a "contested illness" due to doubt about the legitimacy of the condition. It has also come to describe the reactions of some abuse victims beyond the context of kidnappings or hostage-taking.
Actions and attitudes similar to those suffering from Stockholm syndrome have also been found in victims of sexual abuse, human trafficking, terror, and political and religious oppression.