The desire to detect deception has existed as long as acts of deception and both have been pursued across generations in an attempt to gain an advantage over another. The main areas that have been pursued in the study of deception include verbal and nonverbal cues. There are many ways of defining the term deception and many characteristics may be adapted to feature deception behaviour in relation to terrorism. Deception, as a deliberate activity, is employed as a tactic in terrorism activity from the pre-attack planning to the post-attack cover-up stage. A crucial factor that influences deception behaviour is that of stakes, insofar as it refers to the perceived consequences of successful and unsuccessful attempts at deception. There are three main processes involved in conducting deception: the emotional approach, the cognitive effort approach and the attempted behavioural control approach as described in The Multi-Factor Model.