Peter Muris

Maastricht University | UM · Department of Clinical Psychological Science

The current study examined how mood affects the impact of false feedback on belief and recollection. In a three-session experiment, participants first watched 40 neutral mini videos, which were accompanied by music to induce either a positive or negative mood, or no music. Following a recognition test, they received false feedback to reduce belief...

Self-compassion is assumed to have a protective role in the etiology of emotional problems in adolescents. This assumption is primarily based on correlational data revealing negative correlations between the total score on the Self-Compassion Scale (SCS) and symptom measures of anxiety and depression. Recently, however, the SCS has been criticized...

The current study examined how mood affects the impact of false feedback on belief and recollection. In a three-session experiment, participants first watched 40 neutral mini videos, which were accompanied by music to induce either a positive or negative mood, or no music. Following a recognition test, they received false feedback to reduce belief...

Aim The present study examined the relationship between addiction and hikikomori (extreme social withdrawal) symptoms. Method A group of clinically referred addiction patients (n = 31) and a group of age- and gender-matched non-clinical controls (n = 34) completed a self-report scale for measuring hikikomori symptoms (the Hikikomori Questionnaire-...

The present review addressed the relationship between two self-related concepts that are assumed to play a role in human resilience and well-being: self-esteem and self-compassion. Besides a theoretical exploration of both concepts, a meta-analysis (k = 76, N = 35,537 participants) was conducted to examine the magnitude of the relation between self...

Background/aim: Child sexual abuse (CSA) is a pervasive issue that affects children and adolescents worldwide, and Spain is no exception. Despite its high impact, there is a lack of comprehensive data on the prevalence of CSA in Spain. This study aims to update the current state of the prevalence of CSA, providing a comprehensive picture of the pre...

Memories that can be recalled but are no longer believed are termed nonbelieved memories. The current studies examined the creation of emotionally-negative nonbelieved memories after viewing negatively valenced pictures. In both experiments, participants took part in two sessions. In Session 1, after being presented with a set of neutral and negati...

The current study examined the effect of reducing beliefs in the occurrence of traumatic experiences on the production of intrusive memories and the memory amplification effect. Participants took part in two sessions. In the first session, participants rated their emotional state before and after viewing trauma-inducing videos. Then, participants c...

Purpose The aim of the present study was to provide a comprehensive picture of temperament and personality traits as correlates of self-reported disruptive behavior problems in male and female adolescents. Methods Two-hundred-and-sixty-three non-clinical adolescents aged 12–18 years completed a survey containing standardized scales to measure the...

Background: Legal cases and research have shown that due to suggestive therapeutic interventions, people can start to remember abuse that they never experienced. Some of these people eventually retract their claims of abuse. This study examined the memory reports of self-defined retractors of abuse and the prevalence of nonbelieved memories. Method...

The purpose of this study was to study psychopathological and temperamental correlates of selective mutism (SM) (symptoms) in a mixed sample of non-clinical (n = 127) and clinically referred (n = 42, of whom 25 displayed the selective non-speaking behavior that is prototypical for SM) 6- to 12-year-old children. Parents completed questionnaires to...

Although it is widely accepted that human beings have an ingrained ‘need to belong,’ there seem to be a substantial subset of young people who seclude themselves for most of the time at home and no longer engage in education or work, ultimately withdrawing from participation in society. In Japan, this phenomenon has been labeled as ‘hikikomori,’ bu...

Background and purpose: Self-compassion is considered as a protective psychological construct that would shield against the development of emotional problems. The aim of the present study was to compare the 'protective nature' of two measures of self-compassion: the Self-Compassion Scale for Youth (SCS-Y) and the Sussex-Oxford Compassion for the S...

The present study investigated the relative contributions of the Dark Triad, honesty-humility, and other HEXACO traits to externalizing problems in young people. One-hundred-and-six adolescents aged between 12 and 18 years completed an online survey containing the Dirty Dozen for Youth as an index of the Dark Triad traits of psychopathy, Machiavell...

This experimental study examined the role of negative feedback and social rank in the experience of self-conscious emotions, shame and guilt, in typically developing children aged 8 to 13 years. Participants were tested by means of a vignette paradigm in which feedback and social rank were systematically manipulated and levels of shame and guilt we...

In a new commentary in Mindfulness , Neff once again tried to defend the use of the Self-Compassion Scale (SCS) total score by arguing that compassionate and uncompassionate self-responding (CS and UCS) are part of a bipolar continuum. In this brief reaction, we refute this notion and also clarify how the continued use of the SCS total score muddie...

This study examined psychopathological correlates of implicit and explicit shame and guilt in 30 clinical and 129 non-clinical youths aged 8–17 years. Shame and guilt were measured explicitly via two self-reports and a parent report, and implicitly by means of an Implicit Association Test (IAT), while a wide range of psychopathological symptoms wer...

Background There is a notable comorbidity between externalizing disorders and anxiety disorders, which may be explained by the co-occurrence of two prevalent early-onset disorders, by shared vulnerability and risk factors, or as evidence that one disorder group might be causally related to the other. Aim To investigate the longitudinal trajectorie...

Specific fears are a common and normal experience in the life of children and adolescents. In a substantial minority of youths, the fear for a particular stimulus or situation becomes so intense and severe that it starts to interfere with daily functioning, and in these cases the diagnosis of a specific phobia is warranted. In this chapter, we will...

This study adopted a cumulative risk approach to examine the relations between various domains of risk factors (i.e., social isolation and home confinement, other pandemic-related risk factors, and pre-existing psychosocial risk factors) and carers’ and children’s mental health during the first wave of the COVID-19 pandemic in Europe. The sample co...

In current classification systems, selective mutism (SM) is included in the broad anxiety disorders category. Indeed, there is abundant evidence showing that anxiety, and social anxiety in particular, is a prominent feature of SM. In this article, we point out that autism spectrum problems in addition to anxiety problems are sometimes also implicat...

Selective mutism (SM) is a psychiatric condition that is characterized by a failure to speak in specific social situations (e. g., at school) despite speaking normally in other situations (e.g., at home). There is abundant evidence that anxiety, and social anxiety in particular, is a prominent feature of SM, which is the main reason why this condit...

The current experiment examined the effect of forewarning on children’s (11 to 12 years of age) and adults’ spontaneous false memory creation by presenting participants with semantically related word lists that are often used to elicit false memories (i.e., Deese- Roediger-McDermott (DRM) paradigm). The forewarning consisted of an explanation of th...

Selective mutism (SM) is a childhood disorder characterized by a consistent failure to speak in specific social situations (eg, school) despite speaking normally in other settings (eg, at home). This article summarizes evidence supporting the recent classification of SM as an anxiety disorder and discusses the implications of this re-classification...

This chapter consists of the following sections: 1. What are self-conscious emotions? 2. Development of self-conscious emotions 3. Self-conscious emotions and psychopathology 4. Conclusion

Objectives Several scholars have questioned the use of the total Self-Compassion Scale (SCS) score as an appropriate index for measuring self-compassion as a protective psychological trait. Methods We present two new studies to further examine the relationships between SCS or SCS-Short Form scores and symptoms of anxiety and depression in non-clin...

The Dark Triad refers to three malevolent personality traits, namely narcissism, Machiavellianism, and psychopathy. The Dirty Dozen (DD) and Short Dark Triad (SD3) have been developed as concise scales for measuring these traits. This study examined the psychometrics properties of the Spanish version of the DD and SD3 in a non-clinical population r...

Children who are involved in legal cases are often interviewed about events they witnessed or that might have happened to them. Occasionally, after such interviews, children are confronted with misinformation regarding their experiences. The question that arises is whether their earlier interviews may protect them from reporting misinformation. The...

Objectives Falsification is regarded as a cornerstone of science. Anomalous data—even when highly credible—do not always lead to an adjustment of theory. In this paper, we discuss reasons for why current theories are not modified despite a corpus of work falsifying (parts of) the theory, using the case of self-compassion as an example. During more...

The present article reports on a preliminary study exploring the relationships between Dark Triad (narcissism, Machiavellianism, psychopathy) and honesty-humility personality traits and pornography craving and deviant pornography use in a sample of 121 participants (46 men and 75 women) who completed an online survey. Narcissism and psychopathy wer...

This study evaluates the current conceptualization of selective mutism (SM) as an anxiety disorder in the DSM-5 using a meta-analytic approach. In the absence of any systematic assessment of anxiety in the field of SM, we pooled prevalence data of comorbid anxiety disorders in a random-effects meta-analysis. On the basis of 22 eligible studies (N =...

Performing eye movements during memory retrieval is considered to be important for the therapeutic effect of eye movement desensitization and reprocessing (EMDR). We conducted a meta-analysis of laboratory studies that compared the effects of eye movements and/or alternative dual tasks (e.g., counting) on the vividness and emotionality of negative...

Integrating a screening possibility for Autism Spectrum Disorder (ASD) within the widely applied Achenbach System of Empirically Based Assessment (ASEBA) scales could be of great value for daily clinical practice. The present study explored the ability of the school-aged Child Behavior Checklist (CBCL) and the Teacher’s Report Form (TRF) to screen...

De Jongh, A., Muris, P., Merckelbach, H. & Schoenmakers, N. (1996). Suppression of dentist related thoughts. Behavioural and Cognitive Psychotherapy, 24, 117-126.

This longitudinal study explored the relations between fear-enhancing parenting behaviors (modeling and threat information transmission) and children’s cognitive biases and anxiety symptoms on three subsequent time points over a one-year period. Participants were 216 children aged 7–12 years (114 boys and 102 girls), and their mothers (n = 199) and...

Background: Children of chronic pain patients run greater risk for developing chronic pain themselves. Exposure to chronic pain of the parent might install cognitive (e.g., pain catastrophizing, interpretation and attentional bias) and affective (e.g., pain anxiety) vulnerability which increase the risk for the development of chronic pain complain...

Objective To examine the relationship between self-compassion and positive and negative cognitive reactions to daily life problems in a sample of 117 adolescents aged 14–19 years. Method Participants completed a survey containing the Self-Compassion Scale (SCS), the Adolescents’ Reactions to Adversity Questionnaire – a self-developed scale for mea...

The current study compared older children’s (11/12-year-olds) and adolescents’ (14/15-year-olds) vulnerability to false memory creation using two different methods (i.e., the Deese/Roediger-McDermott [DRM] and memory conformity paradigms) involving neutral and negative stimuli. In line with previous research, a developmental reversal effect was fou...

A nxiety is highly prevalent in pre-adolescent children. Distorted cognitions are characteristic for dysfunctional levels of anxiety. However, applying cognitive elements in pre-adolescent children cannot be fully ascertained, as it is not until adolescence before children can apply logical and abstract reasoning in a sophisticated manner. Cognitiv...

In this naturalistic clinical study, we explored the applicability and clinical effectiveness of Cogmed WMT, pharmacotherapy, and their combination for clinically referred children and adolescents with attention-deficit/hyperactivity disorder (ADHD). Ninety youth with ADHD (ages 6–16 years) and their parents were offered the possibility to choose o...

Children are often viewed as poor eyewitnesses. Fact-finders, lawyers, and researchers assume that children are exceptionally prone to accept external suggestive (leading) questions and to create false memories. Is this assumption justified? This review will show it is not. First, studies on spontaneous false memories— elicited without any suggesti...

Suggestibility is regarded as a major issue when children testify in court. Many legal professionals and memory researchers view children as inferior witnesses. Although differences in suggestibility exist between children and adults, they are much more complex than is usually assumed. We show that under certain conditions, adults are more suscepti...

We recently made the case that associative activation is a viable mechanism underlying false memory formation and hence, also false memory formation in psychopathology (Otgaar, Muris, Howe, & Merckelbach, 2017). Tryon (in press) argued that our description of associative activation did not meet the criteria of causation and explanatory value in ord...

To demonstrate that the positive and negative subscales of Self-Compassion Scale (SCS) are very different in nature, we conducted a series of face validity checks on the items of this questionnaire among psychologists and psychology students (Study 1). Furthermore, a survey was administered to a convenience sample of non-clinical adolescents to exa...

Background: This study assesses socio-economic health inequalities (SEHI) over primary school-age (4- to 12-years old) across 13 outcomes (i.e. body-mass index [BMI], handgrip strength, cardiovascular fitness, current physical conditions, moderate to vigorous physical activity, sleep duration, daily fruit and vegetable consumption, daily breakfast...

This study explored the relations between self-conscious emotions, personality traits, and anxiety disorders symptoms in non-clinical youths. One-hundred-and-eighteen adolescents aged 12–15 years completed the brief shame and guilt questionnaire for children (BSGQ-C) and items of the youth self-report (YSR) to measure shame and guilt, the big five...

Research has demonstrated that adequate parenting is an important determinant of a healthy social-emotional development in children. There is a need for valid assessment tools for measuring parenting quality, particularly in clinical settings. The Caregiver Wish List (CWL) is a new 53-item interview-based scale for assessing parenting practices. We...

A specific phobia is an anxiety disorder that is characterized by excessive, unreasonable fear related to a clearly discernible, circumscribed stimulus or situation. The fear response observed in a phobic individual consists of subjective distress, physiological arousal, and avoidance behavior, although its precise expression may vary from one phob...

This study examined the role of theoretically meaningful mediators of therapeutic change-interpretation bias, perceived control, and coping strategies-in a cognitive-behavioral intervention for anxious youth. This is one of the few studies that examined the change in potential mediator and outcome variables by means of a longitudinal design that in...

A cross-sectional study was conducted to examine loneliness and its correlates in children (7 to 11 years) and adolescents (12 to 18 years) with autism spectrum disorders (ASD, n = 73) and control groups of clinically referred (ADHD, n = 76) and non-clinical (n = 106) youths. Youths completed questionnaires on loneliness and desire for social inter...

The present study examined psychological and psychopathological correlates of psychological inflexibility as measured by the Avoidance and Fusion Questionnaire for Youth (AFQ-Y) in two independent samples of nonclinical Dutch adolescents aged between 12 and 18 years (Ns being 184 and 157). Participants completed a survey containing the AFQ-Y and sc...

Background Previous research suggests that it is important to use parental reports when assessing children’s anxiety, but it remains unclear to what extent there are differences between mothers’ and fathers’ scores and whether these potential differences have any repercussions for the psychometric properties of the scale being used. Objective This...

In clinical and court settings, it is imperative to know whether posttraumatic stress disorder (PTSD) and depression may make people susceptible to false memories. We conducted a review of the literature on false memory effects in participants with PTSD, a history of trauma, or depression. When emotional associative material was presented to these...

The present study examined the association between treatment fidelity during therapist initial training and subsequent treatment outcome of Parent Management Training-Oregon model (PMTO) in The Netherlands. Clinically referred children (N = 86) aged 4 to 11 years and their parents received PMTO and were assessed at four time points: at baseline, an...

This study examined relationships between the self-conscious emotions of guilt and shame in both clinical (N = 104) and non-clinical (N = 477) (young) adolescents aged 11–18 years, who completed a questionnaire to assess perceived parental rearing behaviors (EMBU-C) and a scenario-based instrument to measure proneness to guilt and shame (SCEMAS). R...

The Youth Anxiety Measure for DSM-5 (YAM-5) is a newly developed rating scale for assessing anxiety disorder symptoms of children and adolescents in terms of the contemporary classification system. In the present study, 187 children aged 8 to 12 years completed the new measure as well as the trait version of the State-Trait Anxiety Inventory for Ch...

To detect children with dysfunctional levels of fear and anxiety, we need reliable and valid measures that fit the contemporary diagnostic system and suit and support current practices in mental health. Therefore, we developed the Youth Anxiety Measure for DSM-5 (YAM-5), a questionnaire that assesses symptoms of the full range of the contemporary a...

Following publication of this article [1], it has come to our attention that some of the terminology used in the article could be difficult to interpret. In table 1, the description of the measurements should begin with t0. This would mean that t1 becomes t0, t2 becomes t1, and so forth. Furthermore, where schoolchildren are referred to in groups 1...

The term dark triad refers to the constellation of narcissism, Machiavellianism, and psychopathy. Over the past few years, the concept has gained momentum, with many researchers assuming that the dark triad is a prominent antecedent of transgressive and norm-violating behavior. Our purpose in this meta-analytic review was to evaluate (a) interrelat...

Although the Sexual Violence Risk-20 (SVR-20) is widely used, its psychometric properties have only been investigated in a limited number of studies. This study explored the factor structure of the SVR-20 and examined its psychometric properties. Confirmatory factor analysis (CFA) was used to examine the fit of the original three-domain model of th...

The Youth Anxiety Measure for DSM-5 (YAM-5) is a new self- and parent-report questionnaire to assess anxiety disorder symptoms in children and adolescents in terms of the contemporary classification system. International panels of childhood anxiety researchers and clinicians were used to construct a scale consisting of two parts: part one consists...

The present cross-sectional study explored the relations between fear-enhancing parenting behaviors (modeling and threat information transmission) and children's cognitive biases and anxiety symptoms. Participants were 258 children aged 7-12 years (132 boys and 126 girls), and their mothers (n = 199) and/or fathers (n = 117). Children and parents c...

The present study examined the effectiveness of parent management training-Oregon model (PMTO) as a treatment for children with externalizing behavior problems in The Netherlands. Clinically referred children (N = 146) aged 4-11 years and their parents were partly randomized to either PMTO (n = 91) or Care As Usual (CAU; n = 55). Families were asse...

We examined the creation of spontaneous and suggestion‐induced false memories in maltreated and non‐maltreated children. Maltreated and non‐maltreated children were involved in a Deese–Roediger–McDermott false memory paradigm where they studied and remembered negative and neutral word lists. Suggestion‐induced false memories were created using a mi...

This study examined anxiety in preschool children within a South-African context. The parents and teachers of 101 South African children aged 2 to 6 years completed measures of children's anxiety-prone temperament (behavioral inhibition) and anxiety disorders symptoms. Parents and teachers of 59 children could be re-approached one year later, with...

Questionnaire to measure anxiety in children and adolescents (8-18 years) Note: A parent version and adult version are also available via the authors When publishing data gathered with this questionnaire, refer to: DOI: 10.1007/s10578-016-0648-1

A social skills training (SST) for high-functioning children with autism spectrum disorders (ASD) was evaluated in an outpatient setting using a combined between- and within-subject design in which SST and a waiting list condition were compared. According to parents and teachers, the SST produced greater improvement of social skills than the waitin...

Child sexual abuse is associated with social anxiety, low self-esteem, and intimacy deficits. This, in combination with the core belief of a dangerous world, might suggest that child abusers are sexually attracted to submissiveness. The Implicit Association Test (IAT) was used to examine this hypothesis. Results indicated that child abusers have a...

Background Unhealthy lifestyles in early childhood are a major global health challenge. These lifestyles often persist from generation to generation and contribute to a vicious cycle of health-related and social problems. This design article presents a study evaluating the effects of two novel healthy school interventions. The main outcome measure...

The current study examined a number of risk factors that are thought to be related to sexual offending. More specifically, we investigated differences in self-reported aggression, anger, hostility, social anxiety, and social skills between child sexual abusers (n = 28), rapists (n = 36), and nonsexual violent offenders (n = 59) who were detained un...