At a child guidance clinic in Lucknow, a psychologist gives an age-graded intelligence test to two cousins. Ravi is 8 years old and Neha is 15 years old. Ravi solves the tasks that an average 8-year-old solves, but fails those meant for older children. Neha's performance likewise matches the average performance of 15-year-olds, no more and no less. Their grandmother, who watched the session, feels that Neha must be the brighter child because she solved far harder tasks.
Which of the following is correct about the IQs of Ravi and Neha?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Both Ravi and Neha have the same IQ, equal to 100.
Option (1) Both Ravi and Neha have the same IQ, equal to 100. — Correct. IQ is mental age divided by chronological age, multiplied by 100. Each child performs at the average level of his or her own age, so MA equals CA and the IQ equals 100 for both.
Option (2) Neha has a higher IQ than Ravi, as her mental age is higher. — Incorrect. Neha does solve harder tasks, so her mental age of 15 is higher than Ravi's. But it is set against her own age of 15. IQ compares a child with her own age group, so a higher mental age alone does not mean a higher IQ.
Option (3) Ravi has a higher IQ than Neha, as he is the younger child. — Incorrect. Being younger does not raise IQ. Ravi's mental age of 8 matches his age of 8, so his ratio is the same as Neha's.
Option (4) Their IQs cannot be compared, as they are of different ages. — Incorrect. IQ is a ratio, so it can be compared across ages. The average IQ in the population is 100, irrespective of age, so an 8-year-old and a 15-year-old can be compared on it.
NCERT (2026-27): “Assessment of Intelligence … “The mean IQ score in a population is 100. People with IQ scores in the range of 90–110 have normal intelligence. Those with IQ below 70 are suspected to have ‘intellectual disability’, while persons with IQ above 130 are considered to have exceptional talents. …” |