This special issue/section on heart activity as a biomarker to advance our understanding of behavior in intellectual and developmental disabilities (IDD) reflects perhaps a renewed or increased emphasis on integrative studies of behavior and biology in our field and others. In reality, it also reflects editorial serendipity after it was noted that several successive American Journal on Intellectual and Developmental Disabilities submissions had included measures of heart activity as part of their respective study protocols. Subsequently, the contributing authors were approached and asked about considering their papers, after peer review, for a special issue/section on biomarkers and behavior. We express our gratitude for their acceptance of the invitation and patience during the compilation process. We were also fortunate to have had two solicited commentaries from Steve Porges and James Bodfish providing their perspective on the approaches and contributions of the work described herein.
The relation between biology and behavior is...