Lay person’s and psychology officers’ beliefs about memory, investigative interviewing and deception detection: data from Malaysia

It is very typical for people to think that the understanding of psychological phenomena is a matter of common sense. In many parts of the world, the general public and even some professional groups, often express commonly held beliefs about topics in psychology that are not in line with up-to-date scientific literature. To date, comparable data from Malaysia is lacking. In this study, 101 psychology officers serving the Ministry of Home Affairs as well as 130 student and community members in Malaysia completed a survey on beliefs about human memory, detecting lies and police interviews. Generally, participants possessed beliefs that were not in line with current psychological research, which is consistent with findings from many parts of the world. This study serves as an important gauge of the advancement of the field in this region.

Cross-sectional survey study with 231 Malaysian participants (101 psychology officers, 76 participants with psychology background, 54 lay participants) completing validated questionnaires on memory beliefs (Ost et al. 2017 10-item scale), interrogation beliefs (30 statements), and deception detection beliefs, with responses analyzed across professional background groups.

Background & Context

The justice system worldwide depends on assumptions about human behavior that are fundamentally psychological in nature—yet these assumptions are frequently treated as matters of "common sense" rather than scientific evidence. Decisions about policies and laws in the justice system are often based on assumptions about human behaviour, and scholars have spent decades emphasizing the importance of scientific, research-informed practice. However, many psychological misconceptions or false beliefs are based on widely held 'common sense' beliefs, and such misconceptions impede the development and dissemination of accurate knowledge, as well as lead to poor decision-making.

Research from Western countries has documented widespread misconceptions among both professionals and the public about memory functioning, investigative interviewing, and deception detection. Studies from different countries have reported that even professionals exhibit a lack of specialised knowledge about memory, with Norwegian psychologists not performing significantly better than lay people or trial judges. Comparable data from Malaysia was lacking prior to this study, creating a critical gap in understanding whether these patterns of misbelief extend to Southeast Asian contexts.

This study addresses the justice system's profound implications on individual liberties, communities and society as a whole by examining whether psychology officers—professionals trained in psychology and working within Malaysia's Ministry of Home Affairs—hold beliefs aligned with current scientific evidence, or whether they too rely on intuitive but inaccurate "common sense."

Research Design & Methodology

In this study, 101 psychology officers serving the Ministry of Home Affairs as well as 130 student and community members in Malaysia completed a survey on beliefs about human memory, detecting lies and police interviews. One hundred and one participants (52 males, 49 females) aged 29–55 (M = 36.57, SD = 4.22) provided informed consent and completed the questionnaires, with most serving as psychology officers (74.3%), 24 (23.8%) serving as assistant psychology officers.

The lay participant sample comprised 130 Malaysian nationals who have lived in Malaysia for at least 15 years, aged 18–61 (M = 23.72, SD = 7.79), with 25 males and 99 females. For data analyses, all 231 participants were categorised into three groups: psychology officers (n = 101), participants with psychology background (n = 76) and lay participants without psychology background (n = 54).

The survey consisted of multiple validated instruments:

• A memory beliefs questionnaire developed by Ost et al. (2017), which contains 10 statements relating to memory functioning, where participants indicated their level of agreement on a 4-point scale (strongly disagree, disagree, agree, strongly agree), or 'I don't know'
• A questionnaire consisting of 30 confession-relevant statements about interrogation practices
• Items assessing beliefs about behavioral cues to deception
• Questions about how frequently participants read journal articles relevant to research on memory, police interviewing and interrogation, as well as lie detection

The study was not preregistered, but the data and materials are freely available via https://osf.io/36w9y, and was reviewed and approved by the University of Reading Malaysia Research Ethics Committee.

Results & Key Findings

Participants possessed beliefs that were not in line with current psychological research, which is consistent with findings from many parts of the world. This pattern held true across both psychology professionals and lay participants, revealing that specialized training did not necessarily translate to scientifically accurate beliefs.

Memory Beliefs: There were several misconceptions held by most participants, with the controversial idea of unconscious repression of traumatic memories being prevalent. The belief in repressed memories persisted despite most practitioners, especially those who were not research-focussed, being more likely to agree that memories of traumatic events can be repressed and recovered through therapy – a concept that has not been substantiated.

Deception Detection Beliefs: Participants demonstrated reliance on stereotypical but scientifically unsupported cues:

• Both samples were equally likely to believe that hand and leg movements increase during deception, while they have actually been shown to decrease
• Police officers experienced in conducting interrogations as well as civilians held similar stereotyped beliefs as to what behaviours are indicative of lying, for example, gaze aversion
• It is normal for anyone accused of crime to display strong psychological states such as fear and anxiety, hence rendering such cues to be unreliable indicators of deceit, as people's accuracy in distinguishing truth and lies based on nonverbal behaviours is often only at the chance level

Professional vs. Lay Differences: There appears to be a pattern where participants who are or had been previously pursuing psychology and cognate areas at the time of the study held beliefs that are more in line with the state-of-the-art literature, though significant misconceptions persisted even among psychology officers. While it was expected that police officers – whose work involves judgements of honesty in high-stakes contexts – would be more accurate than lay people in their beliefs regarding deceptive behaviour, this was not the case.

Discussion & Significance

The findings reveal a troubling disconnect between psychological science and applied practice in Malaysia's criminal justice system. The overconfidence in the reliability of such cues can lead to misjudgements of one's guilt or innocence, as people's accuracy in distinguishing truth and lies based on nonverbal behaviours is often only at the chance level. This has profound implications for the fairness and accuracy of investigations and adjudications.

The persistence of misconceptions among psychology officers is particularly significant. In the United Kingdom, clinical psychologists who receive extensive training showed more accurate knowledge about memory, which may indicate that expert training and a commitment to engage in the scientific literature can ensure that the professional's practice is evidence-informed. However, the Malaysian data suggest that professional role alone—without ongoing engagement with research literature—is insufficient to overcome intuitive but incorrect beliefs.

These findings align with a summary of studies highlighting that while training can enhance accuracy in deception detection, the effects are minimal. The study contributes crucial comparative data from Southeast Asia, demonstrating that psychological misconceptions transcend cultural boundaries and represent a global challenge for evidence-based practice in forensic and legal settings.

Limitations & Considerations

The study's cross-sectional survey design captures beliefs at a single time point but cannot establish how these beliefs develop or change over time. The reliance on self-reported beliefs may not fully reflect actual practice, as there can be gaps between what professionals believe and how they act in real investigative settings.

The sample, while substantial, was drawn primarily from one region of Malaysia and may not represent the full diversity of beliefs across the country. Most of the participants in the final sample were ethnic Chinese (76.9%), followed by Malay (9.2%), Indian (8.5%), which may not proportionally reflect Malaysia's broader demographic composition.

Additionally, the study did not preregister hypotheses, and while responses were coded with 'strongly agree' and 'agree' as 'accurate' beliefs and 'strongly disagree' and 'disagree' as 'inaccurate' beliefs, some nuance may be lost in this binary classification when scientific consensus itself may be evolving.

Practical Applications

This research underscores an urgent need for evidence-based training programs that go beyond initial professional education. Psychology officers and law enforcement personnel require ongoing exposure to current research, particularly regarding the limitations of behavioral cues in deception detection and the reconstructive nature of memory. Training should explicitly address and correct common misconceptions, using active learning methods rather than passive information transfer.

For consumers of polygraph and forensic services, these findings suggest the importance of seeking practitioners who maintain active engagement with scientific literature and who can articulate the evidence base (and limitations) underlying their methods. This study serves as an important gauge of the advancement of the field in this region and provides a baseline against which future educational interventions can be measured. Policymakers should consider requiring continuing education in psychological science for forensic practitioners, with specific focus on correcting the persistent myths documented in this research.