Developmental relationships as the active ingredient: a unifying working hypothesis of "what works" across intervention settings.

Developmental relationships are characterized by reciprocal human interactions that embody an enduring emotional attachment, progressively more complex patterns of joint activity, and a balance of power that gradually shifts from the developed person in favor of the developing person. The working hypothesis of this article is that developmental relationships constitute the active ingredient of effective interventions serving at-risk children and youth across settings. In the absence of developmental relationships, other intervention elements yield diminished or minimal returns. Scaled-up programs and policies serving children and youth often fall short of their potential impact when their designs or implementation drift toward manipulating other ‘‘inactive’’ ingredients (e.g., incentive, accountability, curricula) instead of directly promoting developmental relationships. Using empirical studies as case examples, this study demonstrates that the presence or absence of developmental relationships distinguishes effective and ineffective interventions for diverse populations across developmental settings. The conclusion is that developmental relationships are the foundational metric with which to judge the quality and forecast the impact of interventions for at-risk children and youth. It is both critical and possible to give foremost considerations to whether program, practice, and policy decisions promote or hinder developmental relationships among those who are served and those who serve. T raditionally rooted in medical and pharmaceutical science, the term active ingredient refers to the critical component of an intervention that is responsible for producing desired change in outcomes (e.g., sodium fluoride in toothpaste). What if everything we do to promote children’s positive development hinges upon a similarly essential element? What if the efficacy of every policy, program, or intervention is determined by whether such effort ultimately promoted or hindered the active mechanisms associated with such an ingredient—the developmental active ingredient? In this article, we advance the working hypothesis that there is such a universally applicable active ingredient underlying effective interventions. We propose that developmental relationships, characterized by attachment, reciprocity, progressive complexity, and balance of power, consistently promote positive development for children and youth across diverse developmental settings. Furthermore, we argue that the effectiveness of child-serving programs, practices, and policies is determined first and foremost by whether they strengthen or weaken developmental relationships. We will first define developmental relationships with sufficient theoretical and operational specificity. Then, using case examples drawn from empirical studies, this working hypothesis is applied to explain what distinguishes effective or ineffective interventions or programs for diverse at-risk populations. We conclude with the practical implications of our hypothesis on program design, professional practice, and policymaking. Competing Hypotheses of Active Ingredients