Multitasking makes it simpler to catch liquids

Multitasking makes it simpler to catch liquids ...

A new technique of lie detection shows that lie tellers who are made to multi-task while being interviewed are easier to spot.

While being questioned, lying during interviews has much greater cognitive energy than telling the truth. A recent study by the University of Portsmouth found that researchers who used this discovery to their advantage by asking a suspect to undertake an additional secondary task were more likely to expose lie tellers. The extra brain capacity required to concentrate on a secondary task (other than lying) was particularly challenging for lie tellers.

The secondary task used in this experiment was to recall a seven-digit vehicle registration number. Only when lie tellers were told that it was important, the secondary task was discovered to be effective.

As long as lie tellers have a good chance to think what they should say, truths are often more plausible than lies.

Professor of Psychology Aldert Vrij

Professor Aldert Vrij, who is studying psychology at the University of Portsmouth, said in the past 15 years that lies can be detected by outsmarting lie tellers. We demonstrated that this may be achieved by forcing lie tellers to divide their attention between completing a statement and a secondary task.

As long as lie tellingers receive a good chance to think, truths often sound more plausible than lies in our experiment. Especially when interviews also had to undertake a secondary task and were told that this task was necessary, our findings have shown that truths and lies can sound equally plausible.

164 participants in the experiment were first asked to give their level of support or opposition about several social topics that they thought were in the news. They then randomly allocated to a truth or lie condition and interviewed about three topics they felt most strongly about. While lie tellers were instructed to lie about their opinions during the interviews.

The structure of results suggests that the introduction of secondary tasks in an interview might facilite lying detection, but these tasks must be carefully introduced.

Professor Aldert Vrij, Psychologist

People who completed the secondary task were given a seven-digit vehicle registration number and were required to return it to the interviewer. Half of them received additional instructions that they may be asked to write down their opinions following the interview if they could not remember the car registration number.

Participants were given the opportunity to prepare themselves for the interview and were informed that it was important to make sure the interview was as convincing as possible, which was inspired by a prize draw.

The findings suggest that lie tellers'' stories appeared to be less plausible and less clear than truth tellers'', particularly when lie tellers were given the secondary task and told that it was important.

According to Professor Vrij, the findings suggest that the introduction of secondary tasks in an interview might facilit lie detection, although such tasks must be carefully introduced. It appears that a secondary task will only be effective if lie tellers do not neglect it. This can be achieved either by telling interviewees that the secondary task is important, as demonstrated in this experiment, or by introducing a secondary task that cannot be neglected (such as gripping an object, holding an object into the air, or driving a car simulator). Secondary tasks that

The study was published in the International Journal of Psychology and Behaviour Analysis.

You may also like: