Final answer:
In middle childhood, children between ages six to ten often join sports teams or structured peer groups like scouts, due to their increasing physical capabilities and desire for social interaction and teamwork.
Step-by-step explanation:
A child in the middle-childhood years, covering the ages of six to ten, is most likely to join a group activity that caters to their increased physical abilities and social awareness. During this life stage, children transition from mostly same-gender play to more mixed-gender groups. They remain interested in solitary play but place a higher emphasis on friendship and group activities. As a result, children in middle childhood often enjoy participating in sports teams, such as Little League Baseball, or become involved in structured peer groups like scouting organizations. They are typically adept at collaborating and sharing, even though occasional feelings of jealousy may surface towards peers or siblings.
At this age, children continue to develop physically, improving agility, balance, and muscle coordination, which enhances their ability to engage in more complex and physically demanding activities. Their cognitive abilities also progress, allowing them to understand and participate in games that require knowledge of rules and fairness. This is a time when children are eager to explore new experiences with friends, learn new skills, and gain a sense of teamwork and accomplishment through group activities.