Chapter 1: Developmental Theory

LEARNING OBJECTIVES

INTRODUCTION

Developmental theory is a scientific attempt to explain how and why humans develop across their life span. A significant amount of human development occurs in the first few years of life as the infant and child learn to move, explore, play, and interact with others. This chapter will introduce some of the most prominent developmental theories and some of the discoveries that help support them. To make sense of the current state in developmental theory, it is important to understand the historical perspectives and discoveries that have helped lead to current understandings. This chapter will begin with a historical perspective of the knowledge about motor development and developmental theory. It will then go over the current principles for understanding the 3 primary developmental theories that explain motor skill acquisition: dynamical systems theory, neuronal group selection theory, and motor programming theory. Cases will be presented to help explain each of these theories to assist in the application of physical therapy clinical practice. Finally, the chapter will discuss an integrative approach of these 3 developmental theories in the skill acquisition of postural control and gait—2 important skills necessary for a child to develop and learn about the world in which they live.

PART I: INTRODUCTION AND HISTORICAL PERSPECTIVES

Developmental Theory: A Progressive Understanding

The science of how and why humans develop is a fascinating journey that has been partly driven by human curiosity and the need to understand why some children struggle with development. Within the past 150 years scientists have advanced their study of the developing infant to gain insight into how humans develop from conception throughout childhood. Around the mid-19th century, an orthopedic physician, John Little, began to take interest in child development when it was observed that early infant birth asphyxiation led to long-term functional deficits in some children.¹ In the late 19th century, the question of nature versus nurture arose, and Sir Francis Galton began to see the influences that genetics had on the development of characteristics and traits in identical and fraternal twins.² Many questions began to arise about how and why humans develop in the way they do. Discoveries led to more questions, which also led to the development of theories that help explain how and why humans develop.

From Maturationism to Developmentalism

Some of our current understandings of human development came from the natural observation of behavior in the ...