In the historical and psychological development of intelligence, tracing from Alfred Binet's tests to the modern Intelligence Quotient (IQ), William Stern proposed the concept of 'Mental Age' and 'Chronological Age' ratio in 1912. Later, Lewis Terman in 1916 modified this in the Stanford-Binet Scale by multiplying it by 100 to establish the modern IQ formula. Based on this, if a child with a chronological age of 10 years has a measured mental age of 12.5 years, what will be the child's actual IQ value according to Terman's modified formula, and under which intellectual category does this score fall statistically?

Understanding the IQ Formula and Calculation

In the history of intelligence testing, William Stern first introduced the concept of the Intelligence Quotient in 1912 as the ratio of Mental Age (MA) to Chronological Age (CA). Later, Lewis Terman in 1916 multiplied this ratio by 100 during the standardization of the Stanford-Binet Intelligence Scale to eliminate decimals, resulting in the modern formula:

IQ = (Mental Age / Chronological Age) × 100

Calculation for the Given Problem:

• Chronological Age (CA) = 10 years
• Mental Age (MA) = 12.5 years
• IQ = (12.5 / 10) × 100 = 1.25 × 100 = 125

Intellectual Classification:

According to standard intelligence classification scales (such as Terman and Wechsler), an IQ score ranging from 120 to 139 is categorized as Superior Intelligence.