Terrorist profiles include the inadequate personality with an excessive, exaggerated demand and 'grand play;' the antisocial personality with a criminal outlook and direct rational expectations; the paranoid with bizarre demands, frequent religious overtones, and underlying homosexual conflicts; and the suicidal hypomanic or depressive. The terrorist group profile consists of the leader (often the paranoid); the activist/operator (the antisocial personality, often a former soldier); and the idealist, who is the most nearly normal and minute functionary in the terrorist enterprise. The Stockholm syndrome is an automatic, unconscious, emotional response to the trauma of becoming a hostage over time. The essential three phases of the syndrome are the hostages' positive feelings toward their captors, negative feelings toward the police, and positive feelings reciprocated by the captors. Negotiators should encourage the development of this syndrome, since it provides a positive bond between captor and hostage which makes it unlikely that the captor will harm the hostages. Negative implications of the syndrome are that the hostages cannot be trusted to cooperate with police during or after the incident, and the hostages may attempt to influence public opinion for the terrorists. 15 references.