Binet decided that a key element in testing intelligence was a child's

• A. standard deviation.
• B. mental age.
• C. emotional intelligence.
• D. practical intelligence.

Answer: (B)

Verified step by step guidance

1. Understand the context: The problem is about identifying a key element in testing intelligence according to Binet.
2. Recognize Binet's contribution: Alfred Binet is known for developing the first practical intelligence test, which introduced the concept of 'mental age'.
3. Clarify the term 'mental age': Mental age refers to the level of intellectual development as compared to chronological age, which Binet used to assess intelligence.
4. Differentiate between the options: Standard deviation is a statistical measure, emotional intelligence refers to understanding emotions, and practical intelligence involves everyday problem-solving skills.
5. Conclude with Binet's focus: Binet emphasized 'mental age' as a crucial element in his intelligence testing, distinguishing it from other forms of intelligence.