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Faculty Spotlight – Iser (“Willie”) DeLeon

How much does Iser (“Willie”) DeLeon enjoy Gainesville and the University of Florida? On sunny mornings, you might find him deliberately parking his car far from the Psychology Building, simply for the opportunity to walk across campus taking in the beauty and vibrant life of the UF campus— reminding himself why he has moved here now for the third time in his life.

DeLeon, who hails originally from Cuba, was a UF undergraduate. As a psychology major, DeLeon was drawn to behavior analysis and received his first exposure to research in Dr. Ed Malagodi’s lab. Even after graduation, one could find him in the psychology building on weekends conducting research as a volunteer. He later earned a Master’s degree from Western Michigan University, but returned to his UF academic roots for a Ph.D., completed in 1997 with Dr. Brian Iwata.

DeLeon’s research has focused on disorders of learning and behavior, mostly involving persons with intellectual and developmental disabilities. After graduation, DeLeon accepted a post-doctoral fellowship at the Johns Hopkins University School of Medicine in Baltimore, MD, and a year later joined the faculty of the Department of Psychiatry and Behavioral Science at Hopkins. For 17 subsequent years, he took up residence on the Inpatient Neurobehavioral Unit at the Kennedy Krieger Institute, one of the Johns Hopkins Medical Institutes and a premiere research and treatment facility for children with neurodevelopmental disorders. DeLeon’s research and clinical activities focused on the assessment and treatment of behavior disorders in children with autism and other developmental disabilities. The inpatient Neurobehavioral Unit is internationally renowned for clinical creativity and innovations with direct links to immediate improvements.

Successful educational and therapeutic programs for children with intellectual and developmental disabilities rely critically on accurate identification of individual preferences and effective rewards. However, this can be challenging because many children lack the ability to express meaningful preferences. Early in his career, DeLeon developed and refined several procedures to permit persons with limited verbal abilities to express their preferences. These procedures have been widely adopted for both research and practice, have inspired numerous replications and extensions, and have helped define the current standard of care. Continuing research in this line seeks to understand the determinants of reward value, a shift from “what is effective” to “why is it effective?” DeLeon and his students examine how contextual variables modify preferences and moderate reward effectiveness over time and experience in both persons with intellectual developmental disorder (IDD) and typically developing adults. For example, recent studies have shown that relative value among rewards can change as a function of the effort required to earn them and that under some circumstances, children prefer delayed over immediate rewards. Consequently, DeLeon is invited regularly to address how best to design reinforcement systems in applied settings.

In 2005, DeLeon assumed the role of Director of Research Development for the Department of Behavioral Psychology at the Kennedy Krieger Institute, designed to enhance programmatic research in the department and foster outside collaborations. His efforts generated over $4,000,000 in NIH funding on projects on which he served as principal investigator and grants he helped others develop. His research agenda evolved at this time towards a translational blend of the aforementioned topics–exploring the implications of basic behavioral processes for designing instructional and therapeutic arrangements—translational research with clinical endpoints. For example, several recent studies and grants interestingly adopted principles of microeconomic theory to predict the efficacy of behavioral interventions across time and exposure.

DeLeon has been recognized as an international leader in this field. He has published roughly 80 papers and chapters in behavior analysis outlets and has delivered dozens of invited lectures and keynotes. He served as Associate Editor for the Journal of Applied Behavior Analysis, the premiere applied research journal in his field and this past fall, and was appointed Editor for Translational Research for the Journal of the Experimental Analysis of Behavior, the flagship basic research journal in behavior analysis. Also in the fall, DeLeon was elected by the Board of Directors of the Behavior Analyst Certification Board©, the international credentialing body for professional behavior analysts, to serve as its president. DeLeon comes to UF with a great deal of academic program building experience. While at Hopkins, he helped to found and administer a new graduate program in behavior analysis at a separate university (University of Maryland, Baltimore County), and served as that program’s director for several years.

Upon returning to UF in 2014, DeLeon quickly established a working relationship with a local, multi-site facility for children with autism spectrum disorders to continue his research in helping this population. He and his students first launched into projects designed to promote tolerance and cooperation during medical and dental exams in children with autism and examine these children’s preferences for different learning arrangements. Relatedly, for his first undergraduate course, he developed a new, and well-received, advanced topics course on Behavior Analysis in Autism. He also continued contributing to program development in behavior analysis, first by renewing approval of our Department’s graduate course sequence towards professional certification in behavior analysis, then securing approval of a new undergraduate sequence that qualifies UF undergraduates to sit for the Board Certified Associate Behavior Analyst examination. Several other programmatic efforts are currently in development.

DeLeon never lost the sense that, at heart, he was a Floridian. As a young undergraduate psychology major at UF, he determined that his dream job would be to teach psychology at the University of Florida. He is now living that dream. His love for this community is perhaps exceeded by his wife’s, Dr. Valerie DeLeon, herself the receipt of several UF degrees (B.A., History, J.D., Law, and M.A., Anthropology), who is now a faculty member in the Anthropology Department at UF. Their two daughters enjoy the nearby beaches and comfortable year-round camping of the Sunshine State, but never let their parents forget that they miss the snow.