M.H. van IJzendoorn

Bio: M.H. van IJzendoorn is an academic researcher from Leiden University. The author has contributed to research in topics: Attachment theory & Attachment measures. The author has an hindex of 28, co-authored 118 publications receiving 5469 citations. Previous affiliations of M.H. van IJzendoorn include Erasmus University Rotterdam.

Disorganized attachment in early childhood: meta-analysis of precursors, concomitants, and sequelae

Abstract: During the past 10 years nearly 80 studies on disorganized attachment involving more than 6,000 infant-parent dyads have been carried out. The current series of meta-analyses have established the reliability and discriminant validity of disorganized infant attachment. Although disorganized attachment behavior is necessarily difficult to observe and often subtle, many researchers have managed to become reliable coders. Furthermore, disorganized attachment shows modest short- and long-term stability, in particular in middle class environments, and it is not just a concomitant of constitutional, temperamental, or physical child problems. The predictive validity of disorganized attachment is established in terms of problematic stress management, the elevated risk of externalizing problem behavior, and even the tendency of disorganized infants to show dissociative behavior later in life. In normal, middle class families, about 15% of the infants develop disorganized attachment behavior. In other social contexts and in clinical groups this percentage may become twice or even three times higher (e.g., in the case of maltreatment). Although the importance of disorganized attachment for developmental psychopathology is evident, the search for the mechanisms leading to disorganization has just started. Frightening parental behavior may play an important role but it does not seem to be the only causal factor involved in the emergence of disorganized attachment.

Sniffing around oxytocin : Review and meta-analyses of trials in healthy and clinical groups with implications for pharmacotherapy

Abstract: The popularity of oxytocin (OT) has grown exponentially during the past decade, and so has the number of OT trials in healthy and clinical groups We take stock of the evidence from these studies to explore potentials and limitations of pharmacotherapeutic applications In healthy participants, intranasally administered OT leads to better emotion recognition and more trust in conspecifics, but the effects appear to be moderated by context (perceived threat of the ‘out-group’), personality and childhood experiences In individuals with untoward childhood experiences, positive behavioral or neurobiological effects seem lowered or absent In 19 clinical trials, covering autism, social anxiety, postnatal depression, obsessive-compulsive problems, schizophrenia, borderline personality disorder and post-traumatic stress, the effects of OT administration were tested, with doses ranging from 15 IU to more than 7000 IU The combined effect size was d=032 (N=304; 95% confidence interval (CI): 018–047; P<001) However, of all disorders, only studies on autism spectrum disorder showed a significant combined effect size (d=057; N=68; 95% CI: 015–099; P<001) We hypothesize that for some of the other disorders, etiological factors rooted in negative childhood experiences may also have a role in the diminished effectiveness of treatment with OT

Serotonin transporter genotype 5HTTLPR as a marker of differential susceptibility? A meta-analysis of child and adolescent gene-by-environment studies.

Abstract: We present results of a meta-analysis of gene-by-environment (G × E) studies involving the serotonin transporter genotype 5HTTLPR to evaluate empirical support for two competing conceptual frameworks in developmental psychopathology: diathesis-stress and differential susceptibility. From a diathesis-stress perspective, the cumulative negative effects of the short allele (ss and sl genotypes) and adverse environments on development have been stressed. From a differential-susceptibility perspective, carriers of the s allele are predicted to be more open to adverse as well as positive environments, for better and for worse. Studies with children and adolescents up to 18 years of age (N=9361) were included. We found 41 effect sizes (N=5863) for the association between negative environments and developmental outcomes with or without significant moderation by 5HTTLPR genotype and 36 effect sizes (N=3498) for the potentially 5HTTLPR-moderated association between positive environments and developmental outcomes. Five moderators were examined: age, ethnicity, genotyping (biallelic or triallelic) and methods used to assess environment and outcome. In the total set of studies, including studies with mixed ethnicities, we found that ss/sl carriers were significantly more vulnerable to negative environments than ll carriers, thus supporting the diathesis-stress model. In the Caucasian samples, however, ss/sl carriers also profited significantly more from positive environmental input than ll carriers. Associations between (positive or negative) environment and (positive or negative) developmental outcome were absent for ll carriers. The meta-analytic findings support the hypothesis that in Caucasian samples 5HTTLPR is a genetic marker of differential susceptibility. G × E interactions might be critically dependent on ethnicity.

Dopamine system genes associated with parenting in the context of daily hassles.

Abstract: The current study examined the molecular genetic foundations of sensitive parenting in humans and is the first to test the interaction between genes and environment in modulating parental sensitive responses to children. In a community sample of 176 Caucasian, middle class mothers with their 23-month-old toddlers at risk for externalizing behavior problems, the association between daily hassles and sensitive parenting was investigated. We tested whether two dopamine-related genes, dopamine D4 receptor (DRD4) and catechol-O-methyltransferase (COMT) gene polymorphisms, modulate parents’ vulnerability to the negative influence of daily hassles on sensitive parenting behavior to their offspring. Sensitive parenting was observed in structured settings, and parents reported on their daily hassles through a standard questionnaire. In parents with the combination of genes leading to the least efficient dopaminergic system functioning (COMT val/val or val/met, DRD4-7Repeat), more daily hassles were associated with less sensitive parenting, and lower levels of daily hassles were associated with more sensitive parenting d = 1.12. The other combinations of COMT and DRD4 polymorphisms did not show significant associations between daily hassles and maternal sensitivity, suggesting differential susceptibility to hassles depending on parents’ dopaminergic system genes. It is concluded that the study of (multiple) gene–environment interactions (in the current case: gene by gene by environment interaction, G × G × E) may explain why some parents are more and others less impacted by daily stresses in responding sensitively to their offspring’s signals.

Visible Learning: A Synthesis of Over 800 Meta-Analyses Relating to Achievement

Abstract: Preface Chapter 1 The challenge Chapter 2 The nature of the evidence: A synthesis of meta-analyses Chapter 3 The argument: Visible teaching and visible learning Chapter 4: The contributions from the student Chapter 5 The contributions from the home Chapter 6 The contributions from the school Chapter 7 The contributions from the teacher Chapter 8 The contributions from the curricula Chapter 9 The contributions from teaching approaches - I Chapter 10 The contributions from teaching approaches - II Chapter 11: Bringing it all together Appendix A: The 800 meta-analyses Appendix B: The meta-analyses by rank order References

Preventing reading difficulties in young children

Abstract: 1 Front Matter 2 Executive Summary 3 Part I: Introduction to Reading 4 1. Introduction 5 2. The Process of Learning to Read 6 Part II: Who Are We Talking About? 7 3. Who Has Reading Difficulties? 8 4. Predictors of Success and Failure in Reading 9 Part III: Prevention and Intervention 10 5. Preventing Reading Difficulties Before Kindergarten 11 6. Instructional Strategies for Kindergarten and the Primary Grades 12 7. Organizational Strategies for Kindergarten and the Primary Grades 13 8. Helping Children with Reading Difficulties in Grades 1 to 3 14 Part IV: Knowledge into Action 15 9. The Agents of Change 16 10. Recommendations for Practice and Research 17 References 18 Biographical Sketches 19 Index