Final answer:
Crying and signs of fear when left alone or with a stranger is known as 'stranger anxiety.' This condition is typical in babies and occurs when a child cannot integrate the stranger into their known mental schemas, often around the time they develop object permanence.
Step-by-step explanation:
Crying and signs of fear when left alone or with a stranger is known as stranger anxiety. This type of anxiety is typically seen in babies around the same time they develop object permanence, according to Jean Piaget's theory of cognitive development. Stranger anxiety manifests through various behaviors such as crying, clinging to a caregiver, or reaching out towards more familiar figures like parents. It occurs when a child is unable to integrate the stranger into their established mental schemas.
It is important to distinguish stranger anxiety from other types of distress and fear that infants may display. For instance, infants showing extreme reactions such as night terrors or being impossible to soothe might be exhibiting signs of deeper issues, which in some cases may even include reactions to abuse, as is the concern with cases of shaken-baby syndrome. Shaken-baby syndrome is a form of physical abuse resulting from violently shaking an infant, leading to severe medical complications such as brain swelling and retinal hemorrhage.
Understanding the normal developmental stages of a child's growth, such as the emergence of stranger anxiety, can help caregivers and parents respond appropriately to their child's needs and ensure their healthy development and wellbeing.