The frequency distribution for the IQ scores tends to approximate a _____.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → bell shaped curve
IQ scores are spread in the population so that the scores of most people fall in the middle range, and only a few people have very high or very low scores. Plotted as a frequency distribution, this gives a bell-shaped curve, called the normal curve, which is symmetrical around the central value, the mean (an IQ of 100).
Option (2) U shaped curve — Incorrect. A U shape would mean that most people have very low or very high IQs and few are average, the reverse of what is found.
Option (3) flat curve — Incorrect. A flat curve would mean that every level of IQ is equally common, with no crowding in the middle.
Option (4) straight line — Incorrect. A rising or falling straight line would mean that the number of people keeps increasing or decreasing steadily with IQ, with no peak at the mean.
NCERT (2025-26): “Assessment of Intelligence … IQ scores are distributed in the population in such a way that the scores of most people tend to fall in the middle range of the distribution. Only a few people have either very high or very low scores. The frequency distribution for the IQ scores tends to approximate a bellshaped curve, called the normal curve. This type of distribution is symmetrical around the central value, called the mean.…” |