Final answer:
An infant's development of control over arms and hands before legs and feet is known as the cephalocaudal trend, which is part of their overall motor development.
Step-by-step explanation:
An infant’s ability to gain voluntary use of arms and hands before legs and feet is an example of the principle of development known as the cephalocaudal trend. This is one of the patterns observed in the motor development of infants, where there is a progression from head to toe. In this pattern, infants first gain control over their head and neck, followed by the upper body and arms, and then later the legs and feet.
As part of their motor skills development, infants also display a number of newborn reflexes, like the grasping reflex, which are inborn automatic responses to stimulation. These reflexes are crucial for survival and development early in life. Over time, as their nervous systems mature, these reflexive actions are replaced by voluntary control, allowing for more complex movements and interactions with their environment.