Exposing an Armed Criminal: What Can We Learn from Psychology and the Police?

Further, a large body of research shows that emotions can have effects that cannot be consciously evaluated but can still have powerful influences on someone’s appearance. Emotion has been found an influential factor for changing body language (Ekman and Friesen, 1967). Such body language may be much more difficult to hide than a weapon and can betray how a person really feels, even when the person attempts to conceal those feelings.
According to several researchers, body language (e.g. gait or changing of posture) might reflect relevant action tendencies that are closely linked with emotional states (Montepare, Goldstein, and Clausen, 1987; de Meijer, 1989; Wallbott, 1998; Hadjikhani and de Gelder, 2003). As an observer of non-verbal behavior one can obtain useful social knowledge about mood and intentions of others, from which one can make decisions concerning required actions. According to Meier-Faust (2002) human body language can be divided into two categories:  structural information (e.g. facial features, body build) and  kinetic information (e.g. facial expressions, gestures, body movements, or posture). Structural information can tell us about what kind of emotion a person is experiencing. Conversely, body movements and posture indicate the intensity of emotion and can physically illustrate what someone feels. This assumption is based on the early research of famous psychologist Paul Ekman who is a pioneer in the study of emotions and facial expressions. Ekman and Friesen (1969) investigated what facial expressions give away about a person. He showed that people who suppress emotional states often 'leak' the true emotion in fleeting facial micro-expressionswhich appear on the face for just 1/25th of a second. These flashes of emotions are beyond our conscious control, making them impossible to be masked. Furthermore, they can be spotted by a trained person. Contrary to what most people believed, he thus found that our facial expressions are not as controlled as we think. Even more surprising, one cannot truly play false with people by showing fake expressions, because there is always a chance that one’s face will betray oneself with inevitable and truly honest micro-expressions.

Nowadays Ekman, as a leading face-reading expert and advisor, is involved in training Transportation Security Administration officers in the United States. This training has become an apparent necessity, as research on emotional and non-verbal behavior has recently received more attention from the security world, possibly as a result of a heightened threat of terrorism. One example of how this research has been put into practice is the  Screening of Passengers by Observation Techniques( SPOT), which is used in aviation and transportation security. It is based on the detection of individuals who show behavior that indicates they may be a threat (The Sunday Times, 2006). There is a strong belief that, rather than finding the threatening object itself (e.g. a concealed weapon, which is possible in too many ways), the identification of the individual bearing the threat is the better way to find the threat. At airports in the US, and recently also at some of the airports in the UK, security teams are present whose responsibility it is to watch travellers while they are entering the airport, checking luggage, or standing in line at security checkpoints. They monitor for readily apparent signs of potential threat such as inappropriate clothing (e.g. a heavy coat on a hot day), as well as more subtle signs which include gestures, conversations, and facial expressions of travelers. By undergoing SPOT training officers are particularly being taught to scan passengers for involuntary physical and psychological reactions that, according to behavioural scientists, may indicate stress, fear or deception. In other words, the officers are trained to recognise concealed emotions which can manifest in overall body movement, gait, or facial expressions.

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