Irwin Waldman

Irwin D. Waldman, Ph.D.

Mapping the Externalizing Spectrum in Youth from an Assessment Perspective

March 2, 2021 (Tuesday)

Learning Objective

Discuss the procedures for determining externalizing symptoms in youth.


While there is considerable research establishing the validity and utility of the Externalizing spectrum of personality and psychopathology in late adolescents and adults, much less is known about Externalizing in youth.  In this presentation, I describe recent research from my lab in which we examine the validity of the Externalizing spectrum in a sample of children and adolescents from an assessment perspective. In two samples, one clinically-referred and the other a population-based sample of twins and their siblings, we tested alternative models of an Externalizing dimension using symptoms of DSM-IV Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD). Rather than treating the data in a typical diagnostic or transdiagnostic fashion, we adopted a psychometric, transdimensional perspective in which the individual symptoms were treated as items on a measure. Specifically, we began by conducting a series of Confirmatory Factor Analyses (CFAs) and Exploratory Structural Equation Models (ESEMs) to test alternative models of Externalizing. We then used Item Response Theory (IRT) methods and concepts to evaluate the item coverage and measurement precision of the resulting Externalizing dimension. Finally, we evaluate the utility of the Externalizing dimension in predicting relevant external criteria and discuss our next steps in extending the Externalizing spectrum in youth to include relevant personality constructs. Our hope is that such methods will increase the validity and utility of capturing Externalizing psychopathology in youth and serve as a model for better-conceptualizing psychopathology and its continuities with personality more generally.


Dr. Irwin D. Waldman is a professor in the Department of Psychology at Emory University. He is head of the Behavior Genetics of Child Personality & Psychopathology Lab at the Center for Translational Social Neuroscience and Center for Quantitative & Computational Genetics. Dr. Waldman is currently Principal Investigator on an NIMH grant to study the molecular genetics of childhood disruptive disorders and is the Co-Principal Investigator on an NIMH grant which funds a behavior genetic study of child externalizing problems.

In my lab we work at the intersection of psychology, statistics, and biology to understand the causes, classification, and biological bases of psychopathology and relevant personality traits. My overarching interests are in developmental psychopathology and developmental behavior genetics. Specifically, we aim to understand the causes, classification, and development of childhood disruptive disorders (e.g., ADHD, Conduct Disorder) and externalizing behavior problems (e.g., aggression, delinquency, psychopathic traits), as well as related personality and temperament traits (e.g., prosociality, Negative Emotionality), social cognitive mechanisms (e.g., perception of facial displays of emotion), and neurocognitive executive functions. A major focus of my research centers on disentangling the genetic and environmental influences that underlie these traits and disorders, as well as understanding how such causal factors combine to influence risk for childhood psychopathology.

I did my undergraduate degree in Human Development and Family Studies at Cornell University, graduating in 1982. While there, I met and became lifelong close friends with Scott Lilienfeld. Following graduation, I attended graduate school in clinical psychology at the University of Waterloo in Ontario, Canada, earning my Ph.D. in 1988. Following my year-long clinical internship at the Lafayette Clinic in Detroit (1987-88), I completed a three-year, NIMH-funded Postdoctoral Fellowship in Behavioral Genetics at the University of Minnesota, where I began a 30-year collaboration with Scott. I then began as a faculty member in the Psychology Department at Emory University in the fall of 1991, which Scott subsequently joined in the fall of 1994. I was a statistical consultant to the DSM-IV Disruptive Behavior Disorders Field Trials, and I am an Associate Editor of the journal Behavior Genetics and currently am on the editorial boards of three other journals (Journal of Abnormal Psychology, Clinical Psychological Science, and Development and Psychopathology). I have also reviewed grants for NIH, as well as for the Medical Research Council and Wellcome Trust in the UK. I was a member-at-large of the Executive Committee of the Behavior Genetics Association (BGA) from 1998-2000, and president-elect, president, and past president of BGA from 2010-2012. I have been a Visiting Faculty Scholar at the Henry A. Murray Research Center at Harvard, a Visiting Professor at the Institute for Behavioral Genetics at the University of Colorado, Boulder, and a Visiting Professor and Honorary Lecturer at the Centre for Social, Genetic, and Developmental Psychiatry Research at the Institute of Psychiatry, University of London, UK. Most recently I’ve been a Visiting Scientist at the Psychiatric and Neurodevelopmental Genetics Unit and Analytic and Translational Genetics Unit at the Massachusetts General Hospital, Harvard Medical School, and a Visiting Scientist at the Broad Institute of Harvard and MIT.