Bowlby suggested that smiling in the infant

A) is random until about 6 months of age.
B) is usually due to gastrointestinal distress.
C) is unrelated to attachment.
D) may serve as a releasing stimulus for affection from others.

Releasing Stimulus

A specific sensory signal that triggers a fixed action pattern or instinctive behavior in animals.

Bowlby

Refers to John Bowlby, a British psychologist known for his pioneering work in attachment theory, emphasizing the importance of early emotional bonds.

Smiling

The act of expressing happiness or approval through a facial expression that involves turning up the corners of the mouth.