This book will introduce you to studies in developmental psychology that changed the way we think about the discipline today. Each chapter provides details of the original work and explains their theoretical and empirical impact, before discussing the ways in which thinking and research has advanced in the years since the studies were first conducted. This edition looks at 16 different studies including topics such as the visual cliff, object permanence, and attachment as well as researchers such as Piaget, Vygotsky, and Ainsworth.