Arrange the following facts related to the correlation of intelligence from the highest to the lowest correlation:
(A) Intelligence of identical twins reared together
(B) Intelligence of fraternal twins reared together
(C) Intelligence of brothers and sisters reared together
(D) Intelligence of identical twins reared apart
(E) Intelligence of siblings reared apart
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (D), (B), (C), (E)
Studies on twins give the evidence for the role of heredity in intelligence: the closer the genetic relation and the more alike the environment, the higher the correlation between the intelligence of two persons.
(A) Identical twins reared together — first, with a correlation of almost 0.90.
(D) Identical twins reared apart — second, 0.72. They share the same heredity but grew up in different environments.
(B) Fraternal twins reared together — third, almost 0.60.
(C) Brothers and sisters reared together — fourth, about 0.50.
(E) Siblings reared apart — last, about 0.25.
NCERT (2025-26): “Intelligence: Interplay of Nature and Nurture … The evidence for hereditary influences on intelligence comes mainly from studies on twins and adopted children. The intelligence of identical twins reared together correlate almost 0.90. Twins separated early in childhood also show considerable similarity in their intellectual, personality and behavioural characteristics. The intelligence of identical twins reared in different environments correlate 0.72, those of fraternal twins reared together correlate almost 0.60, and those of brothers and sisters reared together correlate about 0.50, while siblings reared apart correlate about 0.25.…” |