Final answer:
The grip when infants use their whole hand is known as the Palmer grasp, a reflex that helps maintain close contact with their caregivers for safety and touch needs.
Step-by-step explanation:
When infants grip with the whole hand, it is known as the Palmer grasp. The Palmer grasp is a type of grasping reflex that is present at birth and typically lasts until an infant is about five or six months old.
This instinctive action allows babies to grip an object placed in the palm of their hand, and their grip can be surprisingly strong.
This reflex behavior may have evolved to increase an infant's chances of survival by helping to maintain close physical contact with their caregiver, thereby reducing the likelihood of falling and ensuring they can satisfy their basic need for touch.