Ms Kavita, a school psychologist in Pune, assesses 12-year-old Rohan, who is weak in reading and mathematics, with a battery of verbal and non-verbal tasks developed by Das and Naglieri. Rohan quickly completes designs from which a part has been removed, but finds it hard to recall multiplication tables in order. Before a class test, he sets goals and makes a study timetable. His test performance equals the average performance of 15-year-olds. Rohan has a fraternal twin sister, Riya, brought up in the same home, and their parents ask how alike the twins' intelligence is likely to be.
On the basis of his test performance, what is Rohan's IQ?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 125
Option (1) 80 — Incorrect. 80 comes from turning the ratio upside down, 12/15 x 100. Mental age goes on top.
Option (2) 120 — Incorrect. An IQ of 120 at age 12 would need a mental age of about 14.4.
Option (3) 125 — Correct. Rohan's performance equals the average of 15-year-olds, so his mental age is 15. With a chronological age of 12, his IQ is 15/12 x 100 = 125.
Option (4) 130 — Incorrect. An IQ of 130 at age 12 would need a mental age of about 15.6.
NCERT (2026-27): “Assessment of Intelligence “In 1912, William Stern, a German psychologist, devised the concept of Intelligence Quotient (IQ). IQ refers to mental age divided by chronological age, and multiplied by 100.” |