The Externalizing Consortium was launched in 2017 by Danielle Dick, Ph.D., in partnership with Philipp Koellinger, Ph.D. It is currently led by four research teams, with other significant contributors as follows:

Principal Investigators:

Dr. Danielle M. DickDanielle M. Dick, Ph.D., is Commonwealth Professor of Psychology and Human & Molecular Genetics at Virginia CommonwealthUniversity where she directs a research institute focused on behavioral and emotional health in young people.  Her research focuses on understanding genetic and environmental influences on substance use and related outcomes across development.


Dr. Philipp KoellingerDr. Philipp Koellinger is Professor of Public Affairs at University of Wisconsin-Madison and Professor in Economics at Vrije Universiteit Amsterdam. His research investigates how genes influence economic behavior, and how insights into the genetic architecture of behavioral outcomes can inform social and medical research. He is one of the founders and principal investigators of the Social Science Genetic Association Consortium and the BIG BEAR research consortium.


Dr. Paige HardenDr. Paige Harden is Professor of Psychology at the University of Texas at Austin, where she directs the Developmental Behavior Genetics Lab and co-directs the Texas Twin Project . Her research uses genetic methods to understand the developmental roots of social inequality across the lifecourse. She is the author of The Genetic Lottery: Seeking Equality in a World Where Genes Shape Success, forthcoming in Spring 2021.


Dr. Abraham A. PalmerAbraham A. Palmer, Ph.D., is Professor and Vice Chair for Basic Research in the Department of Psychiatry at the University of California San Diego ( and is the Director of the NIDA National Center of Excellence for GWAS in Outbred Rats . His research explores the genetic and molecular basis of behavior using humans, rats, mice and zebrafish. His other car is a 1977 VW bus.

Lead Analysts:

Dr. Richard Karlsson LinnérRichard Karlsson Linnér, Ph.D., is a postdoctoral researcher with Vrije Universiteit Amsterdam. His research includes investigating the genetic architecture of mental disorders and health-risk behaviors, including smoking, substance use disorders, and addiction, by leveraging large-scale molecular genetic datasets. He dreams of owning a 1977 VW bus, preferably in turquoise.


Travis T. MallardTravis T. Mallard, M.A., is a doctoral candidate at the University of Texas at Austin and a clinical psychology intern at the Veteran Affairs Maryland Health Care System. His research uses genetic methods to understand the etiology of psychopathology with an emphasis on substance abuse and serious mental illness.


Dr. Peter B. BarrPeter B. Barr, Ph.D., is a postdoctoral fellow at Virginia Commonwealth University. His research explores the interplay between shared genetic risk for a variety of psychiatric disorders and social conditions across the lifecourse. In his spare time he aspires to be a slightly above average masters weightlifting competitor.


Dr. Sandra Sanchez-RoigeSandra Sanchez-Roige, Ph.D., is an Assistant Professor at the University of California San Diego and Vanderbilt University. Her newly formed laboratory uses genetic tools to unravel the biology of substance use disorders and comorbid psychopathology, using humans and animal models.

Other Significant Contributors:

Dr. Irwin WaldmanIrwin D. Waldman, Ph.D., is Professor of Psychology, Head of the Behavior Genetics of Child Personality & Psychopathology Lab, and a member of the Center for Quantitative & Computational Genetics at Emory University. His primary research interests are in developmental psychopathology, the structure of psychopathology, and developmental behavior genetics.