Development (of Walking): 15 Suggestions

Abstract

Although a fundamental goal of developmental science is to identify general processes of change, developmental scientists rarely generalize beyond their specific content domains. As a first step toward a more unified approach to development, we offer 15 suggestions gleaned from a century of research on infant walking. These suggestions collectively address the multi-leveled nature of change processes, cascades of real-time and developmental events, the diversity of developmental trajectories, inter- and intraindividual variability, starting and ending points of development, the natural input for learning, and the roles of body, environment, and sociocultural context. We argue that these 15 suggestions are not limited to motor development, and we encourage researchers to consider them within their own areas of research.

Keywords: behavior; exploration; infant; locomotion.

Figure 1.

Numbers correspond to suggestions. (1) Universal stage-like progressions do not represent individual development: motor milestone chart. (2) Skill onset is not an on–off switch: variable developmental trajectory derived from daily observation. (3) Starting points are arbitrary: newborn stepping. (4) Endpoints are arbitrary: woman carrying a heavy load without incurring increased energetic cost. (5) Childrearing alters the onset age and form of skill acquisition: infant exercise and restraint. (6) Experience is not the mere passage of time: the x axis depicts the number of days since skill onset. (7) Natural input shapes learning: the blue line depicts the path of a typical infant during free play. (8) Standard tests are not natural activity: compare red infant footsteps over the gait carpet to blue line in spontaneous walking. (9) Developmental outcomes are not real-time motivations: infants often stop walking without reaching a destination or goal (see location of dots on blue line). (10) Many developing components contribute to skill acquisition: abstraction of multiple, interacting components, each with its own developmental trajectory. (11) Behavior happens in a body in an environment: infant deciding whether and how to descend at the edge of an adjustable drop-off. Possibilities for walking depend on infants’ leg length, balance, and strength relative to drop-off height. (12) Learning occurs in the context of development: overlay of infants’ field of view while crawling and walking.(13) Variability is inherent to development: infants use different strategies to descend a high drop-off (e.g., backing, scooting, crawling). (14) Behavior is a cascade of real-time events: exploratory activity as an infant approaches and navigates an obstacle. (15) New skills instigate a cascade of developmental events: a crawler’s stationary bid for a caregiver’s attention, and a walker’s moving bid for a caregiver’s attention.

Figure I.. Learning to Walk.

(First Row) Steps of a novice infant walking over at ground. (Second Row) Steps of an experienced infant walking over flat ground. (Third Row) Walking steps of an experienced infant approaching and navigating a shallow 6°slope. (Fourth Row) Walking steps of the same experienced infant approaching a steeper 24° slope.