GENERAL INTRODUCTION

Abstract

Almost 150 years after Kussmaul’s documentation of ‘Wortblindheit’ (word blindness) (Kussmaul 1877) the scientific community has generated a number of different theories of dyslexia and dyscalculia. While these theories are still controversially discussed, the converging findings of longitudinal developmental research now allow us to draw an increasingly clear picture of the potential origins of these learning difficulties. At the same time, the common understanding of dyslexia and dyscalculia is blurred by persistent myths, such as the notion that dyslexia causes letters to appear out of order or that dyscalculia is a sign of reduced intelligence. Moreover, families, educators, and even specialized practitioners are often not sure how a specific learning disorder is validly diagnosed and which type of support children need to cope with their difficulties. Accordingly, the purpose of this handbook is to provide a developmentally grounded perspective on these topics by integrating findings from the life sciences and social sciences. Starting with the theoretical foundations of dyslexia and dyscalculia (Part I), we move on to key basic scientific questions, including cognitive, behavioural, genetic, environmental, and neural foundations (Parts II–IV). From there, fundamental discussions are centred on culture, gender, ethnicity, and socioeconomic status (Parts V–VI), before addressing applied aspects of prediction, intervention, and compensation (Parts VII–VIII). Finally, we focus on the best practice in diagnostics, prevention, schooling, and educational policymaking concerning dyslexia and dyscalculia (Parts IX–X). Together, the current work represents the field in its full width and across disciplines. Compact summaries at the end of each part will provide the reader with the essential take-home messages regarding what is known about dyslexia and dyscalculia. The present book is intended to be a one-stop shop for anyone looking for an overview of the state of the art in the field, including researchers, instructors, students, policymakers, educators, teachers, therapists, psychologists, physicians, and, of course, those affected. To keep it accessible to such a broad audience, we took great care to minimize the amount of required prior knowledge of scientific concepts, research methods, statistical models, and technical terms. Furthermore, we tried to maximize its international relevance, wherever possible, by reflecting on the generalizability of the findings to individuals with different national, educational, and cultural backgrounds and by including the currently available literature on non-western-educated-industrialized-rich-democratic (non-WEIRD) populations.