REF2014 Impact Case Study: Cognitive research leads to improved lie detection processes and training adopted by professionals in forensic, intelligence, security and commercial settings

Impact: Other Impacts

Description of impact

The innovative Cognitive Load (CL) technique, based on cognitive theory, yields significantly superior lie detection results. This technique is used for ethical information-gathering interviewing and undercover and interrogation purposes by police, military and intelligence agencies worldwide.

Who is affected

Professionals in forensic, intelligence, security and commercial settings


Research into the concept of the Cognitive Load technique was pioneered by psychology researchers in the Faculty of Science, and is used for ethical information gathering and interviewing. It is generally thought that relying on non-verbal cues to distinguish truth from lies is about 54% accurate. Traditional verbal and non-verbal lie detection is based on the difference in emotions that liars and truth tellers experience. This approach has significant shortcomings and is considered unreliable in determining between lying and the truth. It can also lead to false confessions and unreliable information due to the pressures put on interviewees.
An alternative approach developed in Portsmouth is far more ethical, and non-pressurising as an interview strategy that is more cognitively demanding for liars than truth tellers. The Cognitive Load technique yields significantly superior detection rates (72%). There are several inter-related techniques, which include two main elements: Lying is cognitively more demanding than telling the truth, and unanticipated questioning . This is based on the finding that liars prepare answers when planning for an interview and cannot respond to unanticipated questioning compared to truth tellers.
Training interviewers in the CL technique has taken place across the world and has been used by police and security services as well as by insurance companies. This has resulted in impacts relating to increasing the reliability of detecting criminals. It has also resulted in security businesses adopting the technique- providing an additional level of economic impact.
Impact statusOpen
Category of impactOther Impacts
Impact levelBenefit (delivered impact)


  • REF2014