On Friday, June 1, 2018, when Dr. Thomas Dishion unexpectedly passed away, the silence was palpable and sadness spread around the world, from Tempe to Eugene to Pittsburgh to Charlottesville in the USA, but also in Hamilton (Ontario), Gothenberg (Sweden), Utrecht (Netherlands), and Melbourne. Generations of veteran and junior scholars, as well as aspiring trainees who have been influenced by the plethora of Tom’s impactful contributions, were shaken by this news. Tom touched the lives of scholars, clinicians, and social policy makers through his journal publications, chapters, books, and presentations. His work also changed the lives of countless parents and youth through the development of preventive interventions and the modification of group-based interventions to prevent iatrogenic effects. Tom’s formal and informal mentoring influenced the training and career trajectories of junior (and senior) scholars as well as postdoctoral and graduate students. These mentees were fortunate to learn from a creative genius who possessed an unmatched repertoire of refined methodological skills for conducting both basic and applied research, combined with a genuine passion to improve the human condition, especially the lives of children and adolescents living in sub-optimal environmental contexts.

Tom’s presence will be missed so much because he was consistently creative, visionary, and pioneering across many domains of prevention science and developmental psychopathology. As described in more detail below, Tom would not only use his dissatisfaction with current methods to develop new constructs, he would then collaborate with others to develop new methods for assessing and analyzing critical phenomena in both his basic and intervention research. Whether the focus was on discovering new social interactional processes (e.g., peer deviancy training), identifying limitations of current interactional coding systems (e.g., potential for cultural bias in rating parenting) and current intervention methods (e.g., iatrogenic effects of group-based interventions for adolescents), or developing new intervention methods, Tom was always thinking about next steps in the scientific process—a true preventionist!

Perhaps Tom’s undergraduate education as a philosophy major at the University of California, Santa Barbara, primed him for consistently thinking about the meta-level meaning of his research and specifically its real-world value. After graduating from college, he was “socialized” in the arcane mysteries of behavioral observation at the Oregon Social Learning Center (OSLC), under the mentorship of Gerald Patterson and colleagues, during which time he received his Ph.D. in clinical psychology at the University of Oregon. After 15 years at OSLC, he moved to the University of Oregon, assuming the role of Professor in the Schools of Education and then Department of Psychology, establishing the Center for Families and Children with Beth Stormshak, before moving to Arizona where he founded the Research and Education Advancing Children’s Health (REACH) Institute within Arizona State University’s Department of Psychology.

One of Tom’s early significant contributions was advancing our understanding of social processes essential to the development adolescent problem behavior. Specifically, he focused his attention on the roles of peer influence and parental monitoring (Dishion et al. 1996; Patterson et al. 2000). Following his initial experience at OSLC transcribing audiotapes of home observations of parent-child interactions, one of Tom’s enduring passions became developing observational coding systems that addressed untapped and novel phenomenon. For example, working with anthropologist Jovanna Poe in studying interactions between male teens who were best friends, he observed that the current coding systems were not capturing the topics and the reinforcing systems most relevant to their problem behavior. In response, Tom developed a model for peer deviancy training, including specific observational tasks and coding systems to advance our ability to assess relevant processes (e.g., entropy) that predicted future problem behavior based on peer interactions (e.g., Topic Code, Peer Process Code). In the domain of parenting, while at OSLC, he developed a monitoring task that specifically elicited parental knowledge, or lack thereof. In addition to having youth and parents report on their extent of parental knowledge, Tom devised a family observational task in which youth discussed a time in the recent past when they were alone with friends for multiple hours without adult supervision. This task revealed not only the type of activities youth engaged in with peers, but parental knowledge of their child’s friends and locations they frequented.

Having improved methods for capturing key developmental phenomenon relevant to adolescent problem behavior, Tom turned his attention to improving intervention methods for at-risk youth. In developing and testing his Adolescent Transitions Program, a randomized controlled study for preventing problem behavior, he discovered that one of the three conditions—a teen group that taught social skills—actually led to iatrogenic effects, specifically higher rates of antisocial behavior and substance use. Instead of downplaying or ignoring these findings, Tom made a point of bringing this finding to light and identifying other researchers who might have found similar iatrogenic effects, including the late Joan McCord, along with Francois Poulin, and Ken Dodge. This effort led to a paper published in the American Psychologist (Dishion et al. 1999) and subsequent work (e.g., Dishion and Dodge 2005), including an edited volume (Dodge et al. 2007), all of which emphasized the potential unanticipated consequences of group treatment involving antisocial youth. The American Psychologist paper’s significance was recognized by an award from the Society for Research on Adolescence.

Although always a proponent of evidence-based, social learning parent management programs stemming from his socialization experiences working with Gerald Patterson, Marion Forgatch, Patti Chamberlain, and John Reid at OSLC, he also became concerned with reaching and engaging families reticent to seek services for their adolescents who were struggling emotionally, behaviorally, and/or academically. Capitalizing on the seminal work of Bill Miller and his successful use of motivational interviewing (MI) for intervening with adult alcoholics, Tom adapted and incorporated MI into a preventive intervention for parents with problematic youth, labeling it the Family Check-Up (FCU). Again, only Tom had the genius to “connect the dots” to translate the internal dissonance created by Miller’s use of MI for adults struggling with substance abuse to parents of adolescents dealing with their adolescent’s problem behavior. To address the issue of promoting engagement in FCU (i.e., “If I build it, will they come?”), he wisely embedded the program in middle schools, a place most parents trust. For this revolutionary innovation, Tom received a MERIT Award from NIH to continue following his sample of at-risk youth and parents. MERIT awards are now an extinct species; at that time, it meant an automatic renewal of Tom’s R01 funding for five years.

Again, taking a broad perspective, always open to collaboration and thinking outside the box, with Daniel Shaw, Frances Gardner, and later Melvin Wilson, Tom subsequently adapted the FCU for use in early childhood. Choosing the toddler period was not an accident. Similar to early adolescence, the “terrible twos” capitalized on increases in parental distress during a period of biological and social transition. Instead of schools, the FCU was initially offered at Women, Infants, and Children Nutritional Supplement Centers (WIC), serving a large minority of the United States’ families living in poverty. Not forgetting his developmental roots, the FCU has become one of the few preventive interventions established using a series of RCTs with outcome data spanning more than 10 years for both adolescent and early childhood versions (Caruthers et al. 2014; Shaw et al. 2018). Seals of proven efficacy have been granted for different-age version of the FCU by such evidence-based organizations as Blueprints (early childhood and school-age), SAMHSA’s National Registry of Evidence-based Programs and Practices (adolescent and early childhood), the National Institute of Justice (adolescent) and from the Administration for Children and Families’ Home Visiting Evidence of Effectiveness (early childhood).

Thanks to the accumulation of long-term longitudinal data on intervention outcomes of the FCU, Tom was able to return to his interest in longitudinal modeling developed at OSLC. In addition to studying dynamic system models in coding interactional processes, Tom became interested in using novel analytic methods to go beyond intention-to-treat comparisons between intervention and control groups. He worked with methodologists such as Booil Jo, and in the process, became captivated by comparing youth outcomes of families randomly assigned to the FCU and who engaged in the intervention, with families in the control group who showed similar profiles of sociodemographic and family risk, but did receive the FCU. Tom used Complier Average Causal Effect (CACE) modeling to address the issue of “what would have happened” if intervention families had not received the FCU by comparing the long-term outcomes of actual engagers with matched would-be-engagers in the control group (Dishion et al. 2014).

An inveterate reader, Tom was able to use this knowledge to draw on a broad range of perspectives and integrate models across fields. For example, he incorporated long-term trajectories within life course history, ecological, and evolutionary perspectives. This vantage would lead most scientists to rely on macro-level variables, and indeed he did. However, Tom preferred to employ constructs that vitiate measurement error with ‘true scores’ that tap the intersection of indicators drawing on multiple methods and agents. Yet, he never abandoned his focus on coercive micro- processes within social interaction and their destructive impact on a person’s trajectory over time. Tom’s remarkable talent for communicating enabled him to describe complexities inherent in such work with simplicity and clarity, all the while incorporating ways in which iterations between micro and macro forces can play out.

From the aforementioned description of Tom’s activities and visionary intellect, one might imagine that Tom was not terribly social and preferred to work in isolation. Not the case. Far from it. One of Tom’s fortes was his ability to create and nourish a larger network of like-minded individuals, integrating laughter into serious scientific forums. Maybe from his early years at OSLC, but perhaps also due to his genuine passion to advance the human condition, Tom was concerned with transferring his knowledge to others AND learning from others, whether they be senior superstars, assistant professors, or graduate or undergraduate trainees. If Tom was interested in a topic, he was quick to organize a meeting of researchers to further explore outstanding questions and, in effect, advance the field. In more cases than not, the meeting resulted in a subsequent edited volume or special issue for a journal that cumulatively contributed to the knowledge base. Most recently Tom and the late Jim Snyder put together a sensational volume on coercive relationship processes. While at the University of Oregon, he successfully obtained an NIH training grant for predoctoral and postdoctoral students, so it is no coincidence that many not-so-young-anymore and successful former mentees attribute Tom’s influence as a key in setting their career paths (e.g., Greg Fosco, Rebecca Waller, Erika Lunkenheimer, Isabela Granic, Marie-Helene Veronneau, Timothy Piehler, and Arin Connell, just to name a few).

In terms of his influence through his written word, Tom not only wrote books, chapters, and more than 250 journal articles for academics, but he also crafted books for parents interested in improving their parenting skills. Did we mention that academics appreciated Tom’s research? With an H-index of 97 and over 41,000 citations (Google Scholar), including six papers with more than 1000 citations and 12 papers with more than 500 citations, Tom’s contributions have been appreciated and will continue to be recognized and influential for decades.

Unlike some famous writers, scientists, and artists from history, it is good to know that during his final months, Tom was beginning to enjoy acknowledgement for his work. In a recent conversation, Tom revealed how much he appreciated the recognition of his contributions by others. He was able to savor these accolades despite being physically incapacitated as an enduring result of two serious strokes last fall. Recent reflections of Tom’s influence included being promoted to the lofty title of Regents Professor at and only weeks before his passing, being awarded the American Psychological Association’s (APA) Urie Bronfenbrenner Award for Scientific Contributions in Developmental Psychology. Such commendations of Tom’s contributions are richly deserved and add to his legacy as a Fellow of the Society for Prevention Science (SPR), American Psychological Society, recipient of SPR’s Prevention Science Award (2010), and APA’s Award for Distinguished Contributions to Family Psychology (2006).

What is less known about Tom is his passion for the ethical application of our evidence-based interventions. He taught the graduate seminar on ethics in the Clinical Psychology Program at Arizona State University, where he challenged students to recognize and think through the ethical dilemmas both in clinical work and in promoting and implementing preventive interventions designed to advance the public health. To quote Tom’s syllabus, “The course emphasizes ethical issues that emerge in efforts to integrate intervention science with humane and high quality service delivery.” As a member of a Society for Prevention Research Task Force, Tom was a strong voice in developing the first report of the Society to articulate the ethical challenges encountered in the implementation of preventive interventions.

He was committed to an inclusive process (involving multiple round table discussions, meetings, and internal reviews) to ensure that the report represented the voices of the field. The Final Report of the Task Force (Leadbeater et al. 2018, this issue) bears the stamp of Tom’s strong commitment to identifying the ethical issues in prevention science, and implicitly to a problem solving approach to thinking them through. Tom also walked the ethical walk in his own work on disseminating the Family Check-Up. As described by his collaborator in this work at the ASU REACH Institute, Anne Mauricio, his approach to the ethical dilemmas in dissemination was guided by his strong belief “that program developers and purveyors had a responsibility to empower community agencies to localize quality and implement independently of developers and purveyors. This model involves the transfer of tools and technology that support implementation”, sometimes at the expense of the program developers’ own proprietary self-interest.

Finally, missing from this overview is Tom’s sense of humanity. Although not apparent to those who knew him less well, he suffered serious health problems that severely debilitated him at times. He never uttered a word to friends and colleagues about the challenges he endured while he fought hard to maintain his health, running and biking regularly and pushing himself to the limits. And at the same time, he never faltered in his intensive focus on preventing the negative aspects of the phenomena he studied in an unceasing commitment to uplift families. Those of us who knew him well were constantly amazed at his boundless energy, joy and deep appreciation for the richness of his life. One of the coauthors of this piece (Fishbein), who also suffers from a serious health issue, experienced the very best of Tom, as he called every couple of months for several years just to inquire about her health, minimizing his own challenges.

As one of his former postdoctoral mentees, Greg Fosco put it, “Those than knew him personally were better for it; his intellect, creativity, openness, and optimism helped push forward, and improved our field tremendously.” Tom was giving, kind, and generous with his ideas and time. He enjoyed the outdoors and staying in physical shape, playing and listening to music, having a glass of wine with dinner companions, and appreciated and demonstrated a contagious sense of humor—Tom had a great laugh that punctuated his enjoyment of others. His presence is already sorely missed by the field of prevention science, as a colleague and as an incredible, unforgettable friend.