Final answer:
True, the formation of structured peer groups begins early in development and becomes more significant in middle childhood.
Step-by-step explanation:
The formation of peer groups begins early in a child's development and continues into middle childhood and adolescence. Peer groups play a critical role in socialization, teaching younger children societal norms and as they grow older, providing opportunities for independence and identity development outside the family structure. By the time children reach middle childhood, they increasingly participate in peer-group activities such as sports, which are significant in their social development.
So, to answer the initial question, it is true that while young children have peer interactions, the formation of structured peer groups becomes more pronounced in middle childhood.