Final answer:
An infant is least likely to fear a smiling and friendly stranger, as they prefer human faces and expressions that suggest safety and friendliness. Thus, option A) A smiling and friendly stranger is the correct answer.
Step-by-step explanation:
The characteristics of a "stranger encounter" that an infant is least likely to fear is A) A smiling and friendly stranger.
During the early stages of a child's development, they begin to express stranger anxiety, which is the fear of unfamiliar people. Infants and young children tend to have a preference for human faces, especially those that are smiling and exude friendliness.
This is consistent with attachment theories, such as those proposed by Ainsworth, which suggest that children form different types of attachments with caregivers and display varying responses to strangers based on those attachment styles.
The attachment style described as secure attachment is characterized by a preference for parents over strangers and using caregivers as a secure base from which to explore. Loud or sudden noises, by contrast, are more likely to startle and frighten an infant because they cannot be easily assimilated into their existing schemas of understanding the world around them.