Final answer:
Bailey's mental age is lower than six according to the Binet-Simon Intelligence Scale, which ranks performance against norms for various ages, and indicates Bailey may not be at the typical developmental milestone for their age group in puzzle-solving.
Step-by-step explanation:
In Binet's terms, Bailey's mental age is lower than six. According to the Binet-Simon Intelligence Scale developed by Alfred Binet, mental age refers to the level of intellectual performance as measured by an intelligence test; the performance is compared to average scores of different age groups. Since six-year-olds typically complete a particular block design puzzle in five minutes and it takes Bailey eight minutes, Bailey's performance is indicative of a mental age that is less than six years old, given this specific task and assuming an average performance for six-year-olds.
Cognitive Development in Middle Childhood:
During the period between six and ten years, important cognitive changes take place, where children develop more mature and logical thinking. They begin to concentrate for longer periods and their language skills improve significantly. Understanding these developmental milestones is crucial in evaluating a child's mental age and comparing their performance to normal age group expectations.