ABSTRACT
This chapter focuses on a very basic and practical kind of problem solvingsafely navigating the ground ahead. The problem of mobility is manifold. From their first crawling or walking steps, infants must find their way amidst myriad threats to balance control. The ground is covered with a variety of surfaces-slippery linoleum, deformable playpen mattresses, sloping driveways, and household stairs. Paths are cluttered with furniture, toys, and other obstacles. Interesting places to visit lurk around the corner or behind a door. All the while, infants’ own bodies and skills are continually changing. Infants’ top-heavy proportions gradually slim down, and the ratio of muscle mass to fat increases. Infants’ proficiency at locomotion changes from week to week as babies master belly crawling, progress to hands and knees, cruise sideways along furniture, and finally walk upright.
