Final answer:
Middle childhood in Western nations extends from about age 6 to 12 years, characterized by crucial developments in physical, social, and cognitive domains as children progress through elementary school.
Step-by-step explanation:
According to the text, in Western nations, middle childhood extends from about age 6 to 12 years. Middle childhood is the life stage between early childhood and pre-adolescence. It covers the ages when most children are in elementary school and is marked by significant development in physical abilities, independence, social skills, and cognitive capabilities. Within this period, children become more involved with friends and develop the ability to think in more complex ways.
During middle childhood, children experience steady development in abilities such as agility, balance, and endurance. Their muscle strength and coordination also improve, and movements become more controlled and graceful. Importantly, cognitive skills expand significantly, with thought processes becoming more logical and organized when dealing with concrete information.