There are many people in the field of Aviation Security who feel the problem with aviation Security in the United States is that we are too focused on the item and not the person. Focusing on a passenger’s demeanor and subsequent answers to simple trip story questions can reveal possible deception and maybe even evidence of hostile intent. What we are speaking about is what’s now commonly referred to in the security world as behavior recognition, or as the Israeli’s call it, behavior patter recognition. Behavior recognition, whether done formally or informally, is not new to security and police officials in many parts of the world. However, formally investigating and training behavior recognition is a new approach to security. Security personnel need to be constantly vigilant in recognizing anomalies in our environment. To date, there is no better tool in detecting suspicious human behavior than another human being. Even though untrained security personnel may be familiar with some of the indicators, unless they are “tuned in” to recognizing them and what’s going on around them, they are not going to see them. In this instance, we believe it is important to distinguish ‘looking’ from ‘seeing’, or ‘listening’ from ‘hearing’. The Israelis are renowned for their security procedures when it comes to safeguarding their aviation industry as well as their critical infrastructure and citizens. Many countries have sought out the methods employed by Israel, especially after September. 11. Israel has been using these methods in aviation security for over four decades with perfect success – zero hijackings or airport based attacks. However, they are typically responsible for only 30 flights a day, and thus can employ more detailed hand searches of luggage, interviews of every passenger, and so forth. In contrast, most large US airports are responsible for 30 flights every 30 minutes, and thus all the means available to Israeli security are not available to US Security.
There is nothing magical about behavior recognition and detection. Security officers tell us that they have encountered them on the job, or even as an ordinary traveler, but could never put a face or a name to that “gut feeling” or why the “hair on the back of your head was standing up. The reason is that human body contains many non verbal channels and outlets that help communicate messages to others. For example, body movements such as head, arms, legs, face, and hands all send messages that can express emotions, like anxiety, fear, nervousness, contempt, discomfort, etc.; or cognitions, such as thinking hard, searching memories, thinking on one’s feet, etc. One widely cited figure, although based upon just one study, suggests that 93% of our communication is nonverbal (Mehrabian, 1969). All of the
above involve indicators may present themselves when an individual fears being discovered. That fear of discovery manifests itself in many ways including nonverbal as well as verbal cues. Being successful in deceiving the security process or official is the core feature of all terrorist or criminal acts is deception. Those with malfeasant plans attempt to conceal or mislead others about their intentions or actions. Research has shown that there are some behaviors that are manifestations of human emotion in the face and voice (e.g., Ekman, 2003; Scherer, et al, 1984). However, when individuals attempt to conceal those emotions, or other body states, they engage in deception – which Ekman (1985/2001) defined as a deliberate attempt to mislead, without prior notification of the target of the lie. In contrast to the emotions, to date no researcher has documented a “Pinocchio response;” that is, a behavior or pattern of behaviors that in all people, across all situations, is specific to deception (e.g., Zuckerman, DePaulo, & Rosenthal, 1981).
All the behaviors identified and examined by researchers to date can occur for reasons unrelated to deception. Generally speaking, the research on detecting lies from behavior suggests that two broad families of behavioral clues are likely to occur when someone is lying – clues related to liars’ memory and thinking about what they are saying – cognitive clues – and clues related to liar’s feelings and feelings about deception -emotional clues (DePaulo, Stone, & Lassiter, 1985; Ekman, 1985/2001; Ekman & Frank, 1993; Frank & Ekman, 2004; Knapp & Comedena, 1979; Vrij, 2000; Zuckerman, et al, 1981), signs of behavioral management (Zuckerman, et al, 1981) and lie catcher impression management (self-presentational issues; Buller & Burgoon, Cognitive clues. A lie conceals, fabricates, or distorts information; this involves additional mental effort. The liar must think harder than a truth teller to cover up, create events that have not happened, or to describe events in a way to allow multiple interpretations. Additional mental effort is not solely the domain of the outright liar, however; a person who must tell an uncomfortable truth to another will also engage in additional mental effort to come up with the proper phrasing while simultaneously reducing the potential negative emotional reaction of the other. This extra effort tends to manifest itself with longer speech latencies, increased speech disturbances, less plausible content, less verbal and vocal involvement, less talking time, more repeated words and phrases, and so forth (DePaulo, et al., 2003). Research has also shown that some nonverbal behaviors change as a result of this mental effort. For example, illustrators – hand or head movements that accompany speech, and are considered by many to be a part of speech (e.g., MacNeill, 1992) – will decrease when lying compared to telling the truth (Ekman, 1972; Vrij, 1997). Another way in which cognition is involved in telling a lie is through identification of naturalistic memory characteristics. This means that experienced events have memory qualities that are apparent upon description that are different from events that have not been experienced (the “Undeutsch hypothesis” (named after psychologist Udo Undeutsch who first made this observation; cited in Yuille, 1989). Events that were not actually experienced feature more ambivalence, have fewer details, a poorer logical structure, less plausibility, more negative statements and are less embedded in context. Liars are also less likely to admit lack of memory, and have less spontaneous corrections (reviewed by (DePaulo, et al, 2003; Yuille, 1989), and may use more negative emotion words, and fewer self and other references (Newman, Pennebaker, Berry, & Richards, 2003). Mental effort clues seem to occur more in the delivery of the lie, whereas memory recall clues tend to occur in the content of the lie. We note that not all lies will tax mental effort; for example, it is much less mentally taxing to answer a close ended question like “Did you pack your own bags?” with a yes or no than to answer an open ended “What do you intend to do on your trip?” Moreover, a clever liar can appear more persuasive if he or she substitutes an actual experienced event as their alibi rather than creating an entirely new event. This may be why a recent general review paper (DePaulo, et al., 2003) found consistent non-homogeneous effect sizes for these mental effort and memory based cues across the studies they reviewed, as the particular paradigms used by researchers varied greatly in the extent to which the lies that were studied mentally taxed the liars.