Stephen Porter

• PhD
• Psychology at University of British Columbia - Okanagan

P sychopaths are manipulative, callous, remorseless , impulsive, irresponsible, antisocial individuals with an emotionally barren disposition. Together, these traits often result in aggressive behavior, and our purpose in this chapter is to explore the manner in which, and the reasons why, this may occur. We begin by outlining the contribution of p...

Instantaneous first impressions of facial trustworthiness influence the manner in which observers evaluate ensuing information about stranger targets (e.g., Porter & ten Brinke, 2009). In two studies, we examined the association between perceptions of general trustworthiness and honesty assessments in an extremely high-stakes sample – individuals p...

Corporate corruption has recently called attention to the relevance of psychopathic personality traits—the absence of conscience, remorse, or scruples—in business settings; yet, little is known about how these personality traits affect business practices. We present two studies testing whether psychopathic personality traits are related to social p...

The current study sought to assess whether implicit, emotion-based lie detection is more accurate than explicit lie detection for high-stakes lies. Participants (N = 231) evaluated the honesty of targets - half of whom were sincere and half deceptive killers - making a plea for the return of a missing relative across one of four presentation modali...

Background Debate regarding the potential repercussions of engaging with videogames that promote violence and crime has been part of public discourse for decades. The present study seeks to add to the debate by investigating some of the unexplored links between pro-criminal videogames and antisocial cognitive processes. Aim This study examined whe...

This study differentiated between the language of deceptive and genuine pleaders who were pleading for the return of a missing loved one during a televised press conference. The Wmatrix linguistic analysis tool was used to examine the language of 78 pleaders. Approximately half (n = 35) of these individuals were deceptive and were responsible for t...

Memory researchers long have speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting. With suggestive m...

This study was the first to investigate the relation between Dark Triad personality traits and the experience of schadenfreude. Participants (N = 120) were assigned to one of three priming conditions: empathy, schadenfreude, or neutral. After reading a vignette priming one of the three emotional states, each participant was exposed to a photographi...

Although it is recognized that “dark personalities” engage in a high level of interpersonal manipulation and exploitation, little is known about whether or how they assess a target’s potential vulnerability prior to such behavior. This study examined the relation between the Dark Triad (psychopathy, Machiavellianism, and narcissism) and strategies...

Purpose In many contexts in which high-stakes lies occur (such as security settings or the courtroom), observers must evaluate whether the stories they hear are credible. However, little research has evaluated the ability of observers to detect high-stakes lies, nor the influence of the manner in which the deception is presented on judgment accurac...

Little consensus exists regarding how the details of truthful and false allegations of traumatic victimisation may change over short and long time intervals, yet this cue is utilised in the assessment of witness, victim and suspect credibility. The present study involved a narrative analysis of the details written within 147 sets of allegation stat...

To facilitate a deeper understanding of domestic homicide (DH), the correctional files of 37 male DH perpetrators were examined. Victim, perpetrator and offense characteristics were compared against those from 78 non-domestic homicide perpetrator files to elucidate distinct dynamics. Risk factors preceding DHs were identified retrospectively using...

This article addresses practical implications for preventing lethal and nonlethal domestic violence (DV) that stem from recent research on male domestic homicide perpetrators. The role of risk assessment and batterer intervention programs is emphasized, including specific programming for treatment-resistant perpetrators. Adjunct interventions for r...

We examined the relation between emotion and susceptibility to misinformation using a novel paradigm, the ambiguous stimuli affective priming (ASAP) paradigm. Participants (N = 88) viewed ambiguous neutral images primed either at encoding or retrieval to be interpreted as either highly positive or negative (or neutral/not primed). After viewing the...

Purpose. There is major disagreement about the existence of individual differences in deception detection or naturally gifted detection ‘wizards’ (see O'Sullivan & Ekman, 2004 vs. Bond & Uysal, 2007 ). This study aimed to elucidate the role of a specific, and seemingly relevant individual difference – emotional intelligence (EI) and its subcomponen...

The Dangerous Decisions Theory (DDT; Porter & ten Brinke, 2009) posits that instantaneous perceptions of trustworthiness based on a stranger's face influence the manner in which ensuing information about the target is processed. This study tested a bi-directional DDT model, proposing that information concerning a target's moral behavior could disto...

Although the ability to detect deception is critical in many professional contexts, most observers (including professional lie-catchers) are able to identify deceivers at the level of chance only. Further, almost all studies of deception detection have used low-stakes deception scenarios in determin- ing deceptive behavior and training effectivenes...

Deception evolved as a fundamental aspect of human social interaction. Numerous studies have examined behavioral cues to deception, but most have involved inconsequential lies and unmotivated liars in a laboratory context. We conducted the most comprehensive study to date of the behavioral consequences of extremely high-stakes, real-life deception-...

The human face is a dynamic canvas upon which humans voluntarily and involuntarily display their most intimate feelings. Observers scrutinize the faces of others to make inferences about their emotions, intentions and thoughts. They then use the information they glean from the face to make a myriad of instantaneous inferential judgments, including...

Proponents of Neuro-Linguistic Programming (NLP) claim that certain eye-movements are reliable indicators of lying. According to this notion, a person looking up to their right suggests a lie whereas looking up to their left is indicative of truth telling. Despite widespread belief in this claim, no previous research has examined its validity. In S...

Deception—a fundamental aspect of human communication—often is accompanied by the simulation of unfelt emotions or the concealment of genuine emotions to correspond to the false message. We investigated the consequences of extremely high-stakes emotional deception on the engagement of particular facial muscles, posited by Darwin [Darwin, C. (1872/2...

Darwin (1872) hypothesized that some facial muscle actions associated with emotion cannot be consciously inhibited, particularly when the to-be concealed emotion is strong. The present study investigated emotional “leakage” in deceptive facial expressions as a function of emotional intensity. Participants viewed low or high intensity disgusting, sa...

Emotional deception is a common behaviour that can have major consequences if undetected. For example, the sincerity of an offender's expressed remorse is an important factor in sentencing and parole hearings. The present study was the first to investigate the nature of true and false remorse. We examined facial, verbal and body language behaviours...

According to the dangerous decisions theory (Porter, S., & ten Brinke, L. (2009). Dangerous decisions: A theoretical framework for understanding how judges assess credibility in the courtroom. Legal and Criminological Psychology, 14(1), 119–134), intuitive evaluations of facial trustworthiness influence the interpretation of evidence presented in c...

Purpose. This study used statistical text analysis to examine the features of crime narratives provided by psychopathic homicide offenders. Psychopathic speech was predicted to reflect an instrumental/predatory world view, unique socioemotional needs, and a poverty of affect. Methods. Two text analysis tools were used to examine the crime narrative...

a b s t r a c t This was the first investigation of individual differences in adopting deceptive universal emotional expressions. We hypothesized that psychopathic traits would lead to a heightened ability to suppress emotional expressions and exhibit less ''leakage'' of inconsistent emotions during deceptive displays. Fur-ther, we predicted that e...

Several studies have identified an association between psychopathy and deficits in facial affect recognition. Although this finding is widely seen as providing strong evidence for amygdala dysfunction in psychopaths, this interpretation is challenged by studies finding no recognition impairments. An alternative hypothesis predicts that recognition...

Purpose. Assessing the credibility of reports of sexual victimization – often in the absence of corroboration – presents a significant challenge for legal decision makers. This study examined the accuracy of observers in discriminating genuine and fabricated sexual assault allegations. Further, we examined whether individual differences and cue uti...

The credibility of reports of victimization must be evaluated by police and adjudicators. The present prospective study investigated the features of truthful and fabricated narratives of trauma and their relative consistency over a 6-month period. Participants described both a genuine and fabricated traumatic experience on three occasions over the...

The question of whether discernible differences exist between liars and truth tellers has interested professional lie detectors and laypersons for centuries. In this article we discuss whether people can detect lies when observing someone's nonverbal behavior or analyzing someone's speech. An article about detecting lies by observing nonverbal and...

There is little support for the long-standing assumption that judges and jurors can accurately assess credibility. According to Dangerous Decisions Theory (DDT; Porter & ten Brinke, Legal and Criminological Psychology, 14, 119–134, 2009), intuitive evaluations of trustworthiness based on the face may strongly bias the interpretation of subsequent i...

False allegations of victimization typically are accompanied by malingered emotional symptomology to corroborate claims. This analog study was designed to compare truthful and fabricated symptom profiles on measures of post-traumatic stress (i.e., Revised Impact of Event Scale, Post-Traumatic Stress Disorder (PTSD) Checklist, Trauma Symptom Invento...

The discrimination of genuine and falsified emotional displays is critical in many contexts, including healthcare, forensic, and airport security settings. Previous research has demonstrated that comprehensive (two-day) empirically based deception detection training can lead to moderate gains in judgment accuracy. However, for many professional gro...

In this paper, we provide our view of the current understanding of high-stakes lies often occurring in forensic contexts. We underscore the importance of avoiding widespread pitfalls of deception detection and challenging prevailing assumptions concerning strategies for catching liars. The promise and limitations of each of non-verbal/body language...

This study examined (prospectively) the impact of the emotional content of visual scenes on memory accuracy and susceptibility to misinformation over time. After viewing a highly positive and highly negative photographic image, half of participants ( N = 80) were exposed to misinformation concerning the images and later responded to a series of que...

Defendants commonly claim amnesia for their criminal actions especially in cases involving extreme violence. While some claims are malingered or result from physiological factors, other cases may represent genuine partial or complete amnesia resulting from the psychological distress and/or extreme emotion associated with the perpetration of the cri...

Little is known about the characteristics of homicides committed by more than one perpetrator. This study examined the crime, victim, and perpetrator characteristics of individual homicides (n = 84) versus multi-perpetrator homicides (n = 40), according to official file information from two Canadian federal penitentiaries. Compared to multiple perp...

Purpose. Numerous wrongful convictions have brought into question the ability of judges and juries to accurately evaluate the credibility of witnesses, including defendants. Dangerous decisions theory (DDT) offers a theoretical framework to build our understanding of the decision‐making process that can culminate in such injustices. Arguments. Acco...

Purpose. This study investigated the influence of psychopathy and sex offender subtype on criminal history, probability of being granted conditional release, and performance while on conditional release in a diverse group of violent offenders. We predicted that psychopathic sexual offenders would be associated with relatively prolific violent and s...

a b s t r a c t Past research has linked psychopathic traits with the ability to manipulate others, either through deception or violence. Recent observations in corporate settings suggest that enhanced interpersonal assessments might underlie this process, giving psychopathic individuals the ability to detect useful and/or vulnerable victims. To te...

Although trustworthiness judgments based on a stranger's face occur rapidly (Willis & Todorov, 2006), their accuracy is unknown. We examined the accuracy of trustworthiness judgments of the faces of 2 groups differing in trustworthiness (Nobel Peace Prize recipients/humanitarians vs. America's Most Wanted criminals). Participants viewed 34 faces e...

The widespread supposition that aspects of facial communication are uncontrollable and can betray a deceiver's true emotion has received little empirical attention. We examined the presence of inconsistent emotional expressions and "microexpressions" (1/25-1/5 of a second) in genuine and deceptive facial expressions. Participants viewed disgusting,...

IntroductionRecollections of Traumatic Criminal Experiences: Victims Witnesses and PerpetratorsDeception by and Memory Function in Psychopathic PerpetratorsRecent Research on the Credibility and Memory Qualities of Perpetrators' crime NarrativesFalse Confessions to MurderConclusion Authors' NoteReferences

Purpose. This study examined the verbal and non‐verbal behaviours exhibited by criminal offender and non‐offender participants while they related planned truthful and deceptive accounts about emotional autobiographical events. Methods. In a 2 × 2 (participant group × veracity) quasi‐experimental design, offenders ( N = 27) and university students (...

Despite a large body of false memory research, little has addressed the potential influence of an event's emotional content on susceptibility to false recollections. The Paradoxical Negative Emotion (PNE) hypothesis predicts that negative emotion generally facilitates memory but also heightens susceptibility to false memories. Participants were ask...

According to a long-standing clinical tradition, sexually traumatic experiences are processed and recalled differently from other experiences, often leading to memory impairment. In this study, we compared the characteristics of traumatic memories for sexual violence and two other types of emotional experiences. N=44 women recruited from a local se...

Purpose . Although most people perform around the level of chance in making credibility judgments, some researchers have hypothesized that high motivation and the provision of accurate feedback could lead to a higher accuracy rate. This study examined the influence of these factors on judgment accuracy and whether any improvement following feedback...

Reviews the book, Forensic psychology: Emerging topics and expanding roles by Alan M. Goldstein (see record 2006-13463-000). The main goal of this book is to provide a comprehensive examination of diverse specialized topics related to practice and research in forensic psychology. It was intended to address specialized issues not covered in his F...

We conducted a prospective study with individuals who first described their memories of both a recent traumatic and a highly positive emotional experience in 2001-2002. Of the 49 subjects interviewed after 3 months, 29 were re-interviewed after 3.45 to 5.0 years. Subjects answered questions from a 12-item consistency questionnaire (maximum possible...

Legal decision-makers frequently assess the credibility of reports of traumatic victimization. In this study, we compared the memory features and post-traumatic symptoms associated with truthful and malingered reports of trauma. Participants (N=126) described in writing both a genuine and a fabricated traumatic experience (counterbalanced) and comp...

This study concurrently examined the characteristics of violent actions (homicides) and the manner in which the violent acts are described by the perpetrators. N=50 offenders incarcerated for homicide were classified as psychopathic or non-psychopathic, according to the Psychopathy Checklist-Revised (Hare, 1991, 2003). The instrumentality/reactivit...

In this chapter, the authors begin by outlining the contribution of psychopathy to the prediction of whether and the degree to which a person will engage in aggressive behavior. The authors attention then turns to a much newer focus of research--the characteristics of violent actions by psychopaths. The authors review studies investigating the natu...

This study examined the relative consistency and characteristics of memories for trauma and other non-traumatic emotional experiences over time. A community sample of 52 participants who reported a recent traumatic event were asked to recall both the traumatic and a positive emotional experience in two interviews separated by approximately three mo...

We evaluated parent and teacher ratings of a large sample (N=1579) of elementary-school children in Canada to determine how different conceptualizations of disruptive behaviour are co-related and related to other measures of functioning. Parent and teacher ratings were consistent, and suggested three separate but correlated aspects of disruptive be...

Introduces this special issue of the Canadian Journal of Behavioural Science which places the spotlight on the burgeoning discipline of forensic psychology, one of the most highly respected areas of psychology, in terms of both science and practice. The papers that were selected to appear in this issue are diverse in scope, reflecting the breadth o...

Introduces this special issue of the Canadian Journal of Behavioural Science which places the spotlight on the burgeoning discipline of forensic psychology, one of the most highly respected areas of psychology, in terms of both science and practice. The papers that were selected to appear in this issue are diverse in scope, reflecting the breadth o...

Although a large body of research has established the relevance of psychopathy to adult offenders, its relevance to adolescent offenders is far less clear. The current study evaluated the clinical, psychosocial and criminal correlates of psychopathic traits in a sample of 226 male and female incarcerated adolescent offenders. According to an 18-ite...

In this study, the relationship between psychopathy and the prepetration of sexual homicide was investigated. The official file descriptions of sexual homicides committed by 18 psychopathic and 20 nonpsychopathic Canadian offenders were coded (by coders unaware of Psychopathy Checklist--Revised [PCL--R] scores) for characteristics of the victim, vi...

Responds to the comments by E. F. Loftus (see record 2003-07215-003) on the target articles by A. D. Yarmey (see record 2003-07215-001) and S. Porter et al (see record 2003-07215-002) which both examined the influence of memory (false memory and repressed memory) on adjudication. In Loftus' commentary on the Porter et al article, Loftus agreed w...

Canadian courts are hearing an increasing number of allegations based on historical incidents. In most cases, complainants or witnesses report remembering the alleged offense continuously since its occurrence. In other cases (e.g., R. v François, 1994), a witness reports that his/her memory was "recovered" after being blocked from conscious awaren...

Although distortion is commonly present in memory, the relation between the emotionality of a witnessed scene and susceptibility to mistaken memories is controversial. Participants (N = 90; aged 17-43 years) were recruited for research focusing on "emotional processing" and were not informed that their memories were being investigated. Then, they v...

The present study evaluated how well people are able to identify completely mistaken emotional memories from childhood. Further, possible individual differences, including personality/interpersonal traits and cue utilization strategies, contributing to this ability were examined. 137 participants (aged 17-34 yrs) viewed videos of true and mistaken...

This study investigated the relationship between psychopathy and the characteristics of criminal homicides committed by a sample of 125 Canadian offenders. It was hypothesized that the homicides committed by psychopathic offenders would be more likely to be primarily instrumental (i.e., associated with premeditation, motivated by an external goal,...

Investigated potential factors related to the ability to detect deceit, including characteristics of the credibility assessor (e.g., personality, handedness, cue use), characteristics of the target (attractiveness, gender), and the modality of the report (audio-visual vs audio-only). 310 undergraduate students (aged 18-43 yrs) judged the honesty of...

Using the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991) diagnostic cutoff score of 30, the complete criminal career and community release profiles of 317 Canadian federal offenders (224 low scorers and 93 scoring within the psychopathic range) were investigated. Adult crimes were coded according to age at commission as well as either viol...

According to the traumatic memory argument, traumatic experiences are processed and remembered in a fundamentally different way from other life events. To investigate the validity of this theory, 306 participants were asked to give detailed accounts of two life experiences: their most traumatic experience and their most positive emotional experienc...

There is currently a complex and inconsistent state in the law relating to dissociation and dissociative amnesia (McSherry, 1998). Although dissociative amnesia in defendants is relevant to both competency to stand trial and criminal responsibility in principle, courts have typically assumed a skeptical stance toward such claims in practice. Howeve...

The ability of a group of Canadian federal parole officers to detect deception was investigated over the course of 2 days of lie detection training. On the first day of training, 32 officers judged the honesty of 12 (6 true, 6 fabricated) videotaped speakers describing personal experiences, half of which were judged before and half judged after tra...

In a recent study, more than half of the participants were led to create a partial or complete false memory for an emotional childhood event (e.g., serious animal attack). Using a subsample from that study, we examined the hypothesis that memory distortion is related to characteristics of interviewers and rememberers. The relations between suscepti...

In many countries, such as Canada, police have been increasinglyrelying upon some form of criminal profiling to aid in their serialcrime investigations. A criminal profiler is a psychological consultantor investigator who examines evidence from the crime scene, victims, andwitnesses in an attempt to construct an accurate psychological (usuallyconce...

The authors investigated whether psychopathy would contribute to the understanding of the heterogeneity of sexual violence. Using the Psychopathy Checklist-Revised, presence of psychopathy, callous personality (Factor 1), and chronic antisocial conduct (Factor 2) were examined in a diverse sample (N = 329) of incarcerated sex offenders and nonsexua...

A central issue in the recovered memory debate is whether it is possible to "remember" a highly emotional incident which never occurred. The present study provided an in-depth investigation of real, implanted, and fabricated (deceptive) memories for stressful childhood events. We examined whether false memories for emotional events could be implant...

We examined the hypothesis that reliable verbal indicators of deception exist in the interrogation context. Participants were recruited for a study addressing security effectiveness and either committed a theft to test the effectiveness of a new security guard or carried out a similar but innocuous task. They then provided either (1) a truthful ali...

Despite an impressive body of research spanning seven decades, the causes of psychopathy and psychopathic violence remain enigmatic for mental health professionals and society as a whole. A keystone of the disorder is the absence of normal human emotional experience. In recent years, a predominant view has been that a genetic predisposition is esse...

This paper discusses the research and theoretical underpinnings of statement analysis tehniques for credibility assessment purposes with criminal suspects. Although the principles of statement analysis have long been recognized, only recently have specific techniques been formalized. It is argued that, in seeking patterns of verbal deception in the...

Children with hearing impairments have been found to suffer a high rate of physical and sexual victimization relative to children in general. The purpose of this investigation was to compare the amount and accuracy of the information contained in the eyewitness accounts of deaf and hearing children. Fifteen deaf and 11 hearing children, aged 8 to 1...

One hundred and twenty police recruits (probationer constables) being trained at the Metropolitan Police Training Centre in Hendon, England, participated in 1 of 2 occupational simulations, either nonstressful or stressful. Twenty of the recruits in each condition were active participants in the event, whereas the other 40 were observers. Half of t...