Psychologists from the University of Portsmouth recently led a study that determined that having suspects execute a supplemental activity during questioning can assist officials in determining whether they are being sincere or deceptive. This concept follows earlier studies that postulate that it takes more psychological energy to lie than to remain honest. It is the notion of the researchers that making someone complete another duty while misrepresenting something would make it more difficult to generate a smooth false narrative, making them easier to detect.The findings of the study, published in the International Journal of Psychology & Behavior Analysis, could have implications for law enforcement and investigative procedures.

This study assessed the views of 164 people pertaining to hot topics, such as COVID passports, Brexit, immigration and Prime Minister Boris Johnson. The participants were randomly assigned to be either truth-tellers or liars. The truth-tellers were asked to provide their genuine opinions on the topics, while the liars were instructed to provide false information.

In the course of the question an answer session, two thirds of the participants were bestowed a secondary duty that entailed the recollection and repeating of a motor vehicle registration mark. The researchers subsequently had to decide who was being honest and who was not. Half of this assembly was further advised that the activity was of immense consequence.

The results indicated that tales from liars were judged as unconvincing and not as succinct as the stories spoken by the truth-tellers, particularly when the liars were allocated the secondary task and were alerted to its importance. This suggests that the introduction of a secondary task during an interview could facilitate the detection of lies. However, the researchers emphasized that the task needs to be introduced carefully to ensure its effectiveness. They suggested that the secondary task should either be labeled as important or be something that cannot be neglected by the interviewees.

Professor Aldert Vrij, the lead author of the study, commented that the pattern of results indicates that the integration of secondary tasks into an interview could be beneficial for detecting lies. It is critical for these tasks to not go unnoticed by the interviewee, either by informing them of its relevance or through activities that cannot be disregarded, such as holding an item or manipulating a car simulator. However, any tasks that do not meet these conditions are unlikely to help uncover the truth.

The researchers postulate that their conclusions can be employed in investigative interviewing.By incorporating a secondary task into the questioning process, investigators may be able to enhance their ability to detect deception. This could be particularly useful in situations where it is essential to determine the truth, such as criminal investigations or intelligence gathering.

It is obligatory to point out that the study had certain constraints. Noting this is fundamental since these limitations exist. Firstly, the participants were instructed to lie about their opinions on the controversial topics, which may not accurately reflect real-life situations.The individual's capability and the unique situation can influence the efficacy of the secondary task. Further research is needed to explore the generalizability and reliability of these findings.