The formula to determine I.Q is given by:

The formula to determine I.Q is given by:

Options:

(a) J. B. Watson

(b) Sigmund Freud

(c) Pavlov

(d) Stern

✅ Correct Option: (d) Stern

Explanation:

William Stern, a German psychologist, introduced the formula to calculate Intelligence Quotient (IQ): This formula quantifies intellectual ability relative to age. For example, a child with a mental age of 12 and chronological age of 10 would have an IQ of 120. This method became foundational in intelligence testing and was later adapted in modern standardized tests. PPSC frequently asks this in the context of IQ measurement and educational psychology.

10 Related PPSC Facts:

William Stern = IQ formula creator IQ = (Mental Age / Chronological Age) × 100 Mental age = measured intellectual development Chronological age = actual age IQ 100 = average Above 130 = gifted Below 70 = intellectual disability Basis of early IQ tests Modern tests use standard scores Frequently tested in PPSC pedagogy