Deception According to Hyman (1989) deception implies that an agent acts or
speaks so as to induce a false belief in a target or victim.
Deception can occur in everyday life. Whether it is telling someone
they look nice or not telling them that they look fat. This is an
important process for forming relationships and general social
interaction. However, although this is useful for social interaction,
it is a serious problem in other areas. Deception can be a problem
when people actively deceive in job applications, giving evidence and
in court. Being able to detect whether a person is lying or not in a
criminal situation in very relevant for the legal system to work
effectively. Many people claim to be able to tell whether someone is
lying or not by particular signs. However research shows that this
may not be the case.
In the earliest research into deception, Eckman (1969) suggested that
deception could be detected by leakage cues. It was suggested that
when these ‘micro-expressions’ occur, the person reveals their true
feelings. Further studies looked into verbal and non verbal cues.
Some examples of verbal cues include higher pitch voice, speech
hesitations and taking longer to answer questions. Some examples of
non-verbal cues include twitching, pupil dilation, avoiding eye
contact and increased sweating. However, Ekman (1974) later stated
that no body movement, facial expression or voice change is an
indisputable sign of deceit. However many people that are trained in
lie detection are still taught to use these methods to detect
deception. So how good are people at lie-detection?
Some studies show that the people who one would expect to be good at
lie detection are fairly accurate (eg. Police officers). A recent
study by Mann, Vrij and Bull (2004) showed that when shown videotapes
of real-life lies and truths and found that the officers had an
accuracy of 65%. This was found to be better than lab studies using,
normal (non-trained) participants. Additionally, accuracy was
negatively correlated with popular stereotypical cues such as gaze
aversion and fidgeting. However, although this suggests that human
lie detection is fairly accurate, earlier research has found the
opposite. According to Wallace (1999), psychological research on
deception shows that most of us are poor judges of truthfulness. One
may assume that this only applies to only ordinary people and not
professionals. However further research shows that ‘this applies to
professionals such as police and custom inspectors, whose jobs are
supposed to include some expertise at lie detection’ (Wallace, 1999).
An early study by Kraut and Poe (1980) that custom inspectors showed