William G Iacono

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N218 Elt H

75 E River Rd

In most of my research, family, adoptive, and twin study designs are used to investigate the development and etiology of common mental disorders, including substance use, antisocial, and major depressive disorders. This work is carried out through the Minnesota Center for Twin and Family Research (MCTFR) which I co-direct with colleagues in the Psychology Department and Institute of Child Development.

Teenage drinking and drug use constitute a major public health problem, but it is unclear to what degree the poor long-term outcomes often seen for teen substance abusers are due to the effects of the drugs as opposed to factors that influenced their use the drugs in the first place. A particularly important concern focuses on how substance use affects brain development in youth. Together with collaborators Stephen Malone in the Psychology Department and Sylia Wilson in the Institute for Child Development, my work examines neurocognitive and mental health outcomes for twins who were first studied in pre-adolescence and are now adults. It is known that adolescents who misuse alcohol and illicit drugs show poor psychological adjustment as adults, and they also show signs of brain impairment on neuropsychological tasks and in MRI and EEG studies. However, it is also the case that those at risk for becoming drug abusers in adolescence show some of these same brain characteristics before exposure to drugs and alcohol. Hence, it is not known to what extent the neurocognitive deviations seen in adolescents who misuse substances are the cause or consequence of their drug use. This work, funded by grants from the National Institute on Drug Abuse, involves the study of over 1000 twin pairs, and includes structural and functional MRI measures as well as EEG, neuropsychological, and mental health assessments.

As part of the MCTFR, Monica Luciana and I co-direct the Minnesota site of the Adolescent Brain Cognitive Development (ABCD) project. ABCD comprises a consortium of 21 universities contributing 11,800 pre-adolescent children to a 10-year longitudinal study designed to help us understand the normal variability in adolescent brain and cognitive development and tease apart the many factors that influence it, including how adolescent substance use alters the normal trajectory of neurocognitive development. Minnesota has served as the portal for the recruitment of twin children into ABCD.

I also work collaboratively with Matt McGue on a twin project that examines how adolescent drinking affects mid-life health. In another project, I work with Matt McGue, Scott Vrieze, and colleagues at the University of Colorado on a twin study that is investigating how the legalization of marijuana affects adult psychological adjustment.

I am also interested in the detection of deception. Most of my work in this area deals with the validity of conventionally applied lie detection techniques and their use in forensic settings. However, I am also interested in how novel techniques based on the measure of brain potentials can be used to probe the memory of criminal suspects.

Educational Background & Specialties

Educational Background

  • Ph.D.: Psychology, University of Minnesota, Minneapolis, Minnesota, 1978.


  • clinical psychology
  • psychophysiology
  • brain development
  • the course and development of psychopathology
  • alcoholism
  • drug abuse
  • behavior genetics
  • family and twin study designs
  • lie detection
Courses Taught
  • Psy 4993/8993 - Directed Study: Special Areas of Psychology and Related Sciences: Polygraph Research
  • Psy 4993/5993 - Directed Study: Special Areas of Psychology and Related Sciences: Twin and Family Research
  • Psy 8111 - Psychopathology I
  • Jackson, N. J., Isen, J. D., Khoddam, R., Irons, D., Tuvblad, C., Iacono, W. G., . . . Baker, L. A. (2016). Impact of adolescent marijuana use on intelligence: Results from two longitudinal twin studies. Proceedings of the National Academy of Sciences U S A, 113, E500-508. doi: 10.1073/pnas.1516648113
  • Iacono, W. G. (2018). Endophenotypes in psychiatric disease: Prospects and challenges. Genome Medicine, 10, 11, pp. 1-3. doi: 10.1186/s13073-018-0526-5
  • Iacono, W. G., & Ben-Shakhar, G. (2018). Current status of forensic lie detection with the comparison question technique: An update of the 2003 National Academy of Sciences report on polygraph testing. Law & Human Behavior. doi: 10.1037/lhb0000307
  • Iacono, W. G., Malone, S. M., & Vrieze, S. I. (2017). Endophenotype best practices. International Journal of Psychophysiology, 111, 115-144. doi: 10.1016/j.ijpsycho.2016.07.516
  • Malone, S. M., McGue, M., & Iacono, W. G. (2017). What can time-frequency and phase coherence measures tell us about the genetic basis of P3 amplitude? International Journal of Psychophysiology, 115, 40-56. doi: 10.1016/j.ijpsycho.2016.11.008
  • Wilson, S., Bair, J. L., Thomas, K. M., & Iacono, W. G. (2017). Problematic alcohol use and reduced hippocampal volume: a meta-analytic review. Psychological Medicine, 47, 2288-2301. doi: 10.1017/S0033291717000721
  • Iacono, W. G., Heath, A. C., Hewitt, J. K., Neale, M. C., Banich, M. T., Luciana, M. M., . . . Bjork, J. M. (2018). The utility of twins in developmental cognitive neuroscience research: How twins strengthen the ABCD research design. Developmental Cognitive Neuroscience, 32, 30-42. doi: 10.1016/j.dcn.2017.09.001
  • Harper, J., Malone, S. M., & Iacono, W. G. (2018b). Impact of alcohol use on EEG dynamics of response inhibition: A cotwin control analysis. Addiction Biology, 23, 256-267. doi: 10.1111/adb.12481
  • Harper, J., Malone, S. M., & Iacono, W. G. (2019). Target related parietal P3 and medial frontal theta index the genetic risk for problematic substance use. Psychophysiology, 56, e13383.
  • Regents Professor
  • McKnight Distinguished University Professor
  • Distinguished Scientific Award for an Early Career Contribution to Psychophysiology, Society of Psychophysiological Research, 1982
  • Fellow, American Association for the Advancement of Science, 1986
  • Distinguished Scientific Award for an Early Career Contribution to Psychology, American Psychological Association, 1987
  • Fellow, American Psychological Association, Divisions 1 (General) and 12 (Clinical), 1989
  • Fellow, Association for Psychological Science, 1991.
  • Fellow, American Association of Applied and Preventive Psychology, 1995.
  • President, Society for Psychophysiological Research, 1996-97
  • Distinguished Contribution to Psychophysiology Award (for lifetime scientific achievement), Society for Psychophysiological Research, 2008
  • Distinguished Scientist Award, Society for the Science of Clinical Psychology, 2009.
  • NIH Merit Award, National Institute on Drug Abuse, 2009
  • John Neale Mentorship Award, Society for Research in Psychopathology, 2014
  • Dobzhansky Lifetime Achievement Award, Behavior Genetics Association, 2017