Thomas D Lyon

University of Southern California | USC · School of Law

This study examined children's secret-keeping for a parent and its relation to trust, theory of mind, secrecy endorsement, and executive functioning (EF). Children (N = 107) between 4 and 12 years of age participated in a procedure wherein parents broke a toy and asked children to promise secrecy. Responses to open-ended and direct questions were e...

We investigated the links between questions child witnesses are asked in court, children's answers, and case outcome. Samples of acquittals and convictions were matched on child age, victim–defendant relationship, and allegation count and severity. Transcripts were coded for question types, including a previously under-examined type of potentially...

Part II defines the relevance ratio and explains its relation to probabilistic reasoning. Part Ill uses the ratio to explore the ways in which physicians have misused the term "consistent with sexual abuse" in child abuse cases. Part IV considers whether symptoms "consistent with sexual abuse," although irrelevant for the purpose of proving abuse,...

Eliciting clear descriptions of sexual body parts and abusive touch in child sexual abuse trials is challenging because of children’s immaturity and embarrassment. This study examined references to sexual body part knowledge and sexual touch in attorneys’ questions and 5- to 10-year-old children’s responses (N = 2,247) in 113 child sexual abuse tri...

This study examined 379 4- to 12-year-old children’s answers to any/some and other yes–no questions in forensic interviews about sexual abuse (N = 10,041). Yes–no questions that include the terms any/some (e.g., “Did he say anything?”) often implicitly ask for elaboration when the answer is yes (“What did he say?”). However, children may give unela...

IntroductionAdults are typically poor judges of the veracity of statements, requiring the need for alternative methods for detecting lies. One alternative method to human lie-detectors is using computer-based linguistic analysis which may present a more reliable method for detecting dishonesty. Moreover, while previous research has examined linguis...

Children screened for sexual abuse are typically asked about touch, but their understanding of the meaning of touch has received little direct study. We asked 4- to 9-year-old children (N = 122; M = 6.00, SD = 1.49; 43% male) Yes-No questions (“Is the boy/girl touching the girl/boy?”/“Are the boy and girl touching?”) or Invitations (“What’s happeni...

Background Debates exist regarding whether foster youth should be asked about their placement preferences following removal, with only youth aged 12 years and older at times assumed legally competent to provide input. Objectives The present study evaluated whether placement-related factors known to predict youth's well-being also shape their place...

Background and aims Children's initial reports often play a key role in the identification of maltreatment, and a sizeable amount of scientific research has examined how children disclose sexual and physical abuse. Although neglect constitutes a large proportion of maltreatment experiences, relatively little attention has been directed toward under...

The verbs ask and tell can be used both epistemically, referring to the flow of information, or deontically, referring to obligations through polite requests or commands. Some researchers suggest that children’s understanding of deontic modals emerges earlier than their understanding of epistemic modals, possibly because theory of mind is required...

Background Forensic interviewers are taught to ask children invitations using the word “time” to refer to a specific episode (e.g., “Tell me about the last time he touched you.”). However, children may interpret the word “time” as requesting conventional temporal information rather than narrative information. Objective We examined the rates at whi...

Forensic interviewers ask children broad input-free recall questions about individual episodes in order to elicit complete narratives, often asking about “the first time,” “the last time,” and “one time.” An overlooked problem is that the word “time” is potentially ambiguous, referring both to a particular episode and to conventional temporal infor...

Adolescents tend to be neglected in research examining child sexual abuse (CSA) interviews yet are often said to be particularly reluctant. This study examined reluctance among 119 10- to 17-year-old females questioned about suspected CSA (n = 25,942 responses), utilizing a scheme identifying previously overlooked types of reluctance in commerciall...

Forensic interviewers are taught to pair yes-no questions with open-ended requests for recall in order to reduce the likelihood that they will be misled by false “yes” responses. However, yes-no questions may elicit false “no” responses. Questioning 112 6- to 11-year-old maltreated children about three innocuous events (outside activities, yesterda...

Forensic interviewers are encouraged to elicit a practice narrative from children in order to train them to answer free recall questions with narrative information. Although asking children about their last birthday has been recommended, concerns have been raised that many children will have nothing to report. This study asked 994 4- to 9-year-old...

Adults often fail to recognize the ambiguity of children's unelaborated responses to ‘Do you know/remember (DYK/R) if/whether’ questions. Two studies examined whether sample questions and/or an explicit instruction would improve adults' ability to recognize referential ambiguity in children's testimony. In Study 1 (N = 383), participants rarely rec...

Purpose: Previous research has established that lie-detection accuracy decreases with age; however, various mechanisms for this effect have yet to be explored, particularly when examining the detection of children’s lies. The present study investigated if younger and older adults detect children’s lies using different cues (verbal-content, verbal-a...

When interviewing a child who may have witnessed a crime, the interviewer must ask carefully directed questions in order to elicit a truthful statement from the child. The presented work uses Granger causal analysis to examine and represent child-interviewer interaction dynamics over such an interview. Our work demonstrates that Granger Causal anal...

Concealment (i.e., omitting information without saying anything untrue) has received little empirical attention relative to falsification (i.e., false statements). This study examined free recall reports among a sample of 349 maltreated and non‐maltreated children ages four to nine, and found that concealment of a minor transgression was significan...

Little is known about the relation between law enforcement interviewing behaviors and commercially sexually exploited children’s (CSEC) reluctance. This study examined the relation between officers’ use of maximization, (references to) expertise, minimization, and support and adolescent CSEC victims’ reluctance in a small sample of police interview...

Research has largely overlooked expressions of reluctance in commercially sexually exploited adolescent (“CSEA”) victims. This is problematic because gaining information from known victims is of the utmost importance in order to better serve the needs of current and potential future victims. The current study proposes a novel conceptualization of r...

Objective: Two studies examined 4-7-year-old maltreated children's "I don't know" (IDK) responses to wh- questions after receiving various interview instructions. Hypotheses: We predicted (H1) children would be less inclined to give IDK responses and more inclined to guess to color/number questions compared to other wh- questions; (H2) IDK instr...

In child sexual abuse cases, a central part of the child’s testimony is their description of the abuse episode. However, children often struggle to describe the body mechanics of abuse, and miscommunications are likely. The present study examined questions about the mechanics of abuse in trial transcripts (N = 63) to identify sources of miscommunic...

A consensus has emerged among forensic interviewers that narrative practice rapport building, introducing the allegation with a “why” question about the reason for the interview, and eliciting allegation details with invitations (broad free recall questions) constitute best practice. These methods are favored because they increase true reports with...

The New Jersey Supreme Court held in New Jersey v. J.L.G. (2018) that experts can no longer explain to juries why sexually abused children might deny abuse. The Court was influenced by expert testimony that “methodologically superior” studies find lower rates of denial. Examining the studies in detail, we argue that the expert testimony was flawed...

One common and unfortunately overlooked obstacle to the detection of sexual abuse is non-disclosure by children. Non-disclosure may be expressed via concealment in response to recall questions or via active denials in response to recognition (e.g., yes/no) questions. In two studies, we evaluated whether adults’ ability to discern true and false den...

Forensic interviewers are routinely advised to instruct children that they should indicate when they do not understand a question. This study examined whether administering the instruction with a practice question may help interviewers identify the means by which individual children signal incomprehension. We examined 446 interviews with children q...

The putative confession (PC) instructions (“[suspect] told me everything that happened and wants you to tell the truth”) increases children’s honesty. However, research has shown that children who maintain secrecy despite the PC are more convincing. We examined whether (a) the PC undermines adults’ deception detection abilities or (b) children who...

We propose that young children exhibit an order of encoding bias, such that they are inclined to report or act out events in the order in which they were originally encoded. This bias helps to explain why children assume that events they first hear described are in chronological order and why they often appear to understand “after” better than “bef...

Children’s ability to adequately describe clothing placement is essential to evaluating their allegations of sexual abuse. Intermediate clothing placement (partially removed clothing) may be difficult for young children to describe, requiring more detailed explanations to indicate the location of clothing (e.g., the clothes were pulled down to the...

When a child is suspected to be the victim or sole witness of a crime, the manner in which information is gathered from the child becomes critical. A child forensic interview is the guided conversation that a legal expert conducts to elicit reliable information from a child. To help substantiate child testimony, it is important to discern character...

Automatic speech recognition for child speech has been long considered a more challenging problem than for adult speech. Various contributing factors have been identified such as larger acoustic speech variability including mispronunciations due to continuing biological changes in growth, developing vocabulary and linguistic skills, and scarcity of...

Most child forensic interviewing protocols recommend that interviewers administer a series of ground rules to emphasize concepts that are important to accurately answering interview questions. Limited research has examined whether interviewers follow ground rules recommendations in real-world forensic interviews. In this study, we examined how ofte...

An ongoing challenge for forensic interviewers is to maximize their use of invitations, such as requests that the child “tell me more about” details mentioned by the child. Examining 434 interviews with 4- to 12-year-old children questioned about abuse, this study analyzed (1) faux invitations, in which interviewers prefaced questions with “tell me...

The challenges of dealing with the influx of immigrant children at the United States’ borders are profound. Approximately 5,000 to 10,000 unaccompanied children, including many young adolescents, arrive each month at the southwestern border.1 To determine whether these children will be given safe haven in the United States, authorities question the...

This study explored whether children’s (N=158; 4-9 years-old) nonverbal facial expressions can be used to identify when children are being deceptive. Using a computer vision program to automatically decode children’s facial expressions according to the Facial Action Coding System, this study employed machine learning to determine whether facial exp...

The present study examined the influence of the putative confession (in which children are told that the suspect told them “everything that happened” and “wants [the child] to tell the truth”) and evidence presentation on 9- to 12-year-old maltreated and non-maltreated children’s disclosure (N = 321). Half of the children played a forbidden game wi...

This study examined the role of age, maltreatment status, and executive functioning (EF) on 752 4- to 9-year-old maltreated and nonmaltreated children’s recall disclosure of a transgression in which they appeared to have broken toys while playing with a stranger. Interviewers used narrative practice rapport-building and then questioned children wit...

Although considerable attention has been directed toward the most appropriate placement for children following removal from home due to maltreatment, very little of this attention has focused on children’s stated preferences, particularly when they are young. Specifically, children under 12 years of age are typically presumed incompetent to form re...

Background: Children are often hesitant to disclose transgressions, particularly when they feel implicated, and frequently remain reluctant until confronted with direct questions. Given the risks associated with direct questions, an important issue is how interviewers can encourage honesty through recall questions. Objective: The present study e...

This study examined relations between children’s false statements and response latency, executive functioning, and truth-lie understanding in order to understand what underlies children’s emerging ability to make false statements. A total of 158 (2- to 5- year-old) children earned prizes for claiming that they were looking at birds even when presen...

In this chapter we provide an overview of psychological issues involving children’s capacities as witnesses. First, in order to understand the most important questions for researchers, we discuss the kinds of cases in which children are usually involved. Across different courts, one most often sees children describing abuse at the hands of familiar...

Background: Children alleging sexual abuse rarely exhibit emotion when disclosing, but they may be able to describe their subjective reactions to abuse if asked. Objective: This study examined the extent to which different types of questions in child sexual abuse interviews elicited subjective content, namely emotional reactions, cognitive content,...

Previous research has examined young and middle-aged adults’ perceptions of child witnesses; however, no research to date has examined how potential older adult jurors may perceive a child witness. The present investigation examined younger (18-30 years, N = 100) and older adults’ (66-89 years, N = 100) lie-detection and credibility judgments when...

This study examined relations between children's false statements and response latency, executive functioning, and truth–lie understanding in order to understand what underlies children's emerging ability to make false statements. A total of 158 (2- to 5-year-old) children earned prizes for claiming that they were looking at birds even when present...

The present study examined adults’ (N = 295) interpretations of child witnesses’ referentially ambiguous “yes” and “no” responses to “Do You Know/Remember (DYK/R) if/whether” questions (e.g., “Do you know if it was blue?”). Participants were presented with transcripts from child sexual abuse cases modified based on question format (DYK/R vs. Direct...

The putative confession instruction (“[suspect] told me everything that happened and wants you to tell the truth”) during forensic interviews with children has been shown to increase the accuracy of children’s statements, but it is unclear whether adult’s perceptions are sensitive to this salutary effect. The present study examined how adults perce...

Constructing computational models of interactions during Forensic Interviews (FI) with children presents a unique challenge in being able to maximize complete and accurate information disclosure, while minimizing emotional trauma experienced by the child. Leveraging multiple channels of observational signals, dynamical system modeling is employed t...

Child Forensic Interviewing (FI) presents a challenge for effective information retrieval and decision making. The high stakes associated with the process demand that expert legal interviewers are able to effectively establish a channel of communication and elicit substantive knowledge from the child-client while minimizing potential for experienci...

Children’s memories for their conversations are commonly explored in child abuse cases. In two studies, we examined conversational recall in 154 4- to 9-year-old children’s reports of an interaction with a stranger, some of whom were complicit in a transgression and were admonished to keep it a secret. Immediately afterwards, all children were inte...

The current study tested the effects of two interview techniques on children's report productivity and accuracy following exposure to suggestion: implicit encouragement (backchanneling, use of children's names) and the putative confession (telling children that a suspect "told me everything that happened and wants you to tell the truth"). One hundr...

Asking children about conversations may both elicit allegations and aid in assessing allegations. Seventy-one children (5 - 9-year-olds) engaged in toy play with a confederate that ended in toy breakage, and were then questioned about their interaction. After one week, they were questioned by a second interviewer, who asked both free recall questio...

This study examined the utility of two interview instructions designed to overcome children's reluctance to disclose transgressions: eliciting a promise from children to tell the truth and the putative confession (telling children that a suspect "told me everything that happened and wants you to tell the truth"). The key questions were whether the...

Children’s potential confusion between “ask” and “tell” can lead to misunderstandings when child witnesses are asked to report prior conversations. The verbs distinguish both between interrogating and informing and between requesting and commanding. Children’s understanding was examined using both field (i.e., Study 1) and laboratory (i.e., Studies...

Children’s descriptions of clothing placement and touching with respect to clothing are central to assessing child sexual abuse allegations. This study examined children’s ability to answer the types of questions attorneys and interviewers typically ask about clothing, using the most common spatial terms (on/off, outside/inside, over/under). Ninety...

Children, if questioned in a supportive manner, are capable of providing enormous amounts of productive information in response to open-ended questions. The irony is that many direct and suggestive methods once thought necessary to overcome abused children's reluctance to disclose abuse have been found counterproductive in two ways: they minimize t...

“Do you know” and “Do you remember” (DYK/R) questions explicitly ask whether one knows or remembers some information while implicitly asking for that information. This study examined how 104 4- to 9-year-old children testifying in child sexual abuse cases responded to DYK/R wh- and yes/no questions. When asked DYK/R questions containing an implicit...

"Do you know" and "Do you remember" (DYK/R) questions explicitly ask whether one knows or remembers some information while implicitly asking for that information. This study examined how 104 4- to 9-year-old children testifying in child sexual abuse cases responded to DYK/R wh- and yes/no questions. When asked DYK/R questions containing an implicit...

This study examined the effects of credibility-challenging questions (n = 2,729) on 62 5- to 17-year-olds’ testimony in child sexual abuse cases in Scotland by categorizing the type, source, and content of the credibility-challenging questions defence lawyers asked and assessing how children responded. Credibility-challenging questions comprised 14...

This study examined the effects of secret instructions (distinguishing between good/bad secrets and encouraging disclosure of bad secrets) and yes/no questions (DID: “Did the toy break?” versus DYR: “Do you remember if the toy broke?”) on 262 maltreated and non-maltreated children's (age range 4–9 years) reports of a minor transgression. Over two-t...

This study examined the effects of the hypothetical putative confession (telling children “What if I said that [the suspect] told me everything that happened and he said he wants you to tell the truth?”) and negatively valenced yes/no questions varying in their explicitness (“Did the [toy] break?” vs. “Did something bad happen to the [toy]?”) on tw...

Purpose: Previous research has demonstrated that attorney question format relates to child witness' response productivity. However, little work has examined the relations between the extent to which attorneys provide temporal structure in their questions, and the effects of this structure on children's responding. The purpose of the present study...

The underlying reasons for recantation in children’s disclosure of child sexual abuse (CSA) have been debated in recent years. In the present study, we examined the largest sample of substantiated CSA cases involving recantations to date (n = 58 cases). We specifically matched those cases to 58 nonrecanters on key variables found to predict recanta...

This study examined whether maltreated children are capable of judging the location and order of significant events with respect to a recurring landmark event. One hundred sixty-seven 6- to 10-year-old maltreated children were asked whether the current day, their last court visit, and their last change in placement were "near" their birthday and "b...

Purpose: The present study examined how children alleging sexual abuse are asked about clothing placement during abusive episodes, both in criminal trials and forensic interviews. The placement of clothing is of great importance, because it facilitates distinguishing abusive touch from non-abusive touch, as well as the severity of abuse when the to...

Children are often the primary source of evidence in maltreatment cases, particularly cases of child sexual abuse, and may be asked to testify in court. Although best-practice protocols for interviewing children suggest that interviewers ask open-ended questions to elicit detailed responses from children, during in-court testimony, attorneys tend t...

Ross Cheit’s book The Witch-Hunt Narrative highlights the difficulties of prosecuting child sexual abuse. Drawing examples from a single case, Alex A., we examine the ways in which false acquittals of sexual abuse are likely to occur. First, prosecutors tend to question children in ways that undermine their productivity and credibility. Second, pro...

Wh- prompts (what, how, why, who, when, where) vary widely in their specificity and accuracy, but differences among them have largely been ignored in research examining the productivity of different question-types in child testimony. We examined 120 6- to 12-year-olds’ criminal court testimony in child sexual abuse cases to compare the productivity...

Child witnesses are often asked wh- prompts (what, how, why, who, when, where) in forensic interviews. However, little research has examined the ways in which children respond to different wh- prompts and no previous research has investigated productivity differences among wh- prompts in investigative interviews. This study examined the use and pro...

Purpose: This study examined the effects of the putative confession (telling the child that an adult “told me everything that happened and he wants you to tell the truth”) on children’s disclosure of a minor transgression after questioning by their parents. Methods: Children (N = 188; 4 – 7-year-olds) played with a confederate, and while doing so,...

This study examined the effects of repeated questions (n = 12,169) on 6- to 12-year-olds' testimony in child sexual abuse cases. We examined transcripts of direct- and cross-examinations of 120 children, categorizing how attorneys asked repeated questions in-court and how children responded. Defense attorneys repeated more questions (33.6% of total...