What is primarily responsible for enabling infants to perform coordinated movements as they grow?

Brain development is primarily responsible for enabling infants to perform coordinated movements as they grow. As the brain matures, it establishes neural pathways and networks that facilitate motor skills. This development helps infants to gain control over their muscles and refine their movements. Specifically, areas of the brain responsible for motor control, such as the cerebellum and the motor cortex, play crucial roles in planning and executing movements.

While muscle strength, reflexes, and nutrition are important aspects of overall development, they do not solely account for the coordination and fine-tuning of movements. Muscle strength is certainly necessary for physically executing movements, but without the proper brain development to guide those movements, strength alone would not lead to coordinated actions. Reflexes are involuntary responses that do not require conscious thought; they play a role in immediate responses but are not responsible for the learned, coordinated movements that develop as infants grow. Nutrition is vital for supporting overall growth and brain development, but it is the development of brain structure and function that directly enables coordinated movement skills.