【正文】 unication system, and emergency illumination system. Such systems may be essential to successful emergency egress, particularly to those unfamiliar with the facility. Uncertainty and confusion during initial stages of an emergency, for example, might cause individuals to (1) delay evacuation from a deadly threat, which could prove ultimately fatal, or (2) behave nonadaptively and trigger a stampede. Exposure to an effective emergency munication system, on the other hand, which providesinformation about the emergency and safe egress, could decrease uncertainty and confusion. The abovementioned characteristics are interdependent, and may simultaneously impact occupants’ behaviors during an emergency. Much development on the subject can be referred to the work of Sime (1984), Bryan (1997), Proulx and Sime (1991), and Shields and Proulx (2000). Psychological and Social CharacteristicsHuman and social behaviors in emergency situations may be described sychologically and sociologically at three levels: individual, interaction among individuals, and group. These three levels of categorization are intimately related and interdependent. IndividualA crowd is a collection of individuals. In order to understand crowd behaviors, we need to first study the individual’s behaviors. From a human cognitive psychological perspective, individual’s behaviors can be viewed as the outes of the individual’s decisionmaking processes. We conjecture that an individual’s decisionmakingprocesses follow three basic conventions: instinct, experience, and bounded rationality. An individual may select one or a bination of these basic conventions when faced with emergencies, depending on the specifics of the situation.? Instinct. Instinct refers to inborn patterns of behavior responsive to specific stimuli. Executing an instinct does not require conscious thought process. Examples of human instincts are fear, death and survival. While human infants typically function by instinct, Wills (1998) claims that adult behavior can also be largely explained in terms of instinct, and that human adults can experience and act on instincts without being conscious of them. Adult nowledge learned through life experience can be viewed as extension of instinct. When there is a need to make decisions under high stress, following one’s instincts is the most primitive way that an individual relies on in making instantaneous and quick decisions. According to Quarantelli (1954), if an individual perceives that he/she is in an extreme lifethreatening situation, his/her behaviors are likely to be driven by the fear instinct such as fight or flight. Behaviors, such as pushing others down, jumping out of windows, and fleeing towards deadly blocked exits, occur because of fear.? Experience. An individual often relies heavily on his/her personal experiences in making decisions. Because many life events are highly repetitive, an individual usually develops a set of relatively standard routines over time or from past experience and then applies them to similar situations in the future. In the case of emergency egress, it is widely recognized that an individual’s experiences can significantly impact his/her behavior (Bryan, 2003。 Society of Fire Protection Engineers, 2002。 Horiuchi et al., 1986。 Sime, 1986), such as the familiarity of the surroundings, safety procedures, and fire drills. However, “using prior evacuation experience to guide future evacuation decisions, may or may not produce better outes” (Averill et al., 2005, ). One observed phenomenon is that most people tend to exit a building following the route with which they are mostfamiliar and ignore alternate routes. Decisionmaking in terms of following experience is usually straightforward and quick. The process typically follows three basic steps: (1) recognize a situation that is the same as or similar to an experience in the past。 (2) retrieve the routines that were successful according to prior experience。 and (3) carry out the routines.? Bounded rationality. The idea of bounded rationality has been integrated into many conventional social theories and e to dominate most theories of individual decision making (March, 1994). Rational decisionmaking assumes decisions are based on evaluation of alternatives in terms of their consequences for preferences. The process involves four basic steps: (1) search for possible options。 (2) anticipate consequences of each option。 (3) weigh each consequence against preferences。 and (4) choose the most favorable option. Such a decision process is bounded because typically, not all options are known, not all consequences are considered, and not all preferences are evoked simultaneously. Decisionmaking in terms of bounded rationality is concerned with bining new facts with existing knowledge for problemsolving, and it is one of the fundamental characteristics that constitute human intelligence. The resulting solution usually is more appropriate for the given situation pared to a solution obtained through either following instinct or experience。 but the “rational” decision making process does require a longer processing time. In an emergency situation where decisions need to be made instantly, an individual may opt for a faster method by simply following instincts or experiences, resulting at times to what is referred to as irrational behaviors (Le Bon, 1960). On the other hand, altruistic and prosocial behaviors are monly observed in emergencies (Bryan,2003。 Horiuchi et al. 1986) which would seem to imply rational thinking during emergencies. Rational or irrational behaviors, thus depend significantly on time and severity as perceived by each individual. Emergency decisionmaking differs from other types of decisionmaking in at least three ways: (1) higher stakes, (2) higher uncertainty, and (3) limited time (Proulx, 2002). According to the crisis model developed by Billings et al (1980), these would lead to increase