Immediate behavioral and emotional responses to attack are difficult to predict, in part because there are so many types of attack. It is possible, however, to specify some dimensions of attacks, each of which conditions the nature of the response:
The suddenness of the attack: from immediate and unanticipated (e.g., bombings) to slowly unfolding (the spread of infectious viruses).
The scope of the attack: highly localized (e.g., the bombing of one building) to broadly destructive (such as the successful disruption of much of the nation’s electric power system or the explosion of a nuclear device over or in a metropolitan center).
Whether the attack is a one-time event or there are multiple attacks.
If attacks are multiple, whether spacings are regular, irregular, or random.
Whether the attack is local (e.g., the isolated attack on a fuel pipeline) or general (release of an infectious virus or toxification of mail or currency).
The level of knowledge about the agent of attack: known, suspected, unknown, unknowable.
The degree to which a target is symbolically neutral (e.g., the blowing up of a railroad track) or symbolically charged (bombing of the White House or the U.S. Congress).
The degree to which an attack appears to be grossly inhumane (e.g., attacks on innocent urban populations, attacks on children).
Because of this variability, the principles involved have to be advanced with a sense of contingency, not certainty, and in an other-things-being-equal spirit. That caution ventured, the following principles, based on best-available behavioral and social science knowledge, can be enunciated:
Outright “behavioral” panic will be rare. It is most likely to occur under special conditions when escape routes are clogged or believed to be closing, and if people learn (or it is rumored or imagined) that there is only limited time to escape (Quarantelli, 1977). Some scenarios for panic would be attempting to escape entrapment in a building, trying to evacuate a metropolitan area under crisis conditions, and fleeing from an assault on a mass gathering in a stadium or arena.
Psychological panic (fear, hysteria, terror) is more likely, and its intensity will vary according to the level of uncertainty about the scope of the attack, its duration, the degree to which it is to believed to be general, and the agent of attack.
The more multiple or random the attacks, the greater the level of public terror.