Final answer:
To ease the anxiety of a five-year-old girl in an initial social work interview, the social worker should use play materials to establish a connection and build trust.
Step-by-step explanation:
In an initial interview with a five-year-old girl who is anxious and emotionally constricted, the social worker should first relate to the child through the use of play materials to lower anxiety and begin a working relationship. Utilizing play materials and activities is an effective way to engage young children, as it allows them to express themselves in a non-threatening environment. At this age, children are still in Erikson's initiative versus guilt stage, and they can develop a sense of trust when they feel safe and understood through interactive play. This method is beneficial for easing anxiety and helping children open up, which aligns with their cognitive and emotional development, as theorized by Piaget and Erikson.