Figure 2.

Hypothetical trajectories from birth toward level of readiness to learn and participate in preschool at 3 years of age. The hypothetical onsets of object interaction, sitting, and locomotion behaviors are indicated by the circle, triangle, and square, respectively, on each trajectory. In the typical development trajectory, object interaction, sitting, and locomotion emerge in the first year of life and act as vehicles to provide children with the tools needed to be successful in school. In the trajectory for children who have developmental delays and are provided ineffective or no early intervention services, object interaction, sitting, and locomotion behaviors emerge later and are performed less frequently and less variably—resulting in poorer cognitive development and lack of readiness to learn and participate by preschool age. The trajectory for children with developmental delays shows how this situation can be transformed with effective early intervention targeting early perceptual-motor behaviors to advance cognition and readiness to learn in school.