Arrange, in order of highest correlation to lowest the hereditary influences on intelligence on twins.
A. Siblings reared apart have the lowest correlation.
B. Identical twins reared together correlate almost 0.90.
C. Fraternal twins reared together correlate almost 0.60.
D. Identical twins separated in childhood display considerable similarity.
E. Brothers and sisters reared together have average correlation.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → B, D, C, E, and A
(B) Identical twins reared together correlate almost 0.90. — the highest: the same genes and the same home.
(D) Identical twins separated in childhood display considerable similarity. — the same genes in different environments still correlate 0.72.
(C) Fraternal twins reared together correlate almost 0.60. — fewer shared genes, the same home: 0.60.
(E) Brothers and sisters reared together have average correlation. — about 0.50.
(A) Siblings reared apart have the lowest correlation. — about 0.25, the lowest of all.
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.…” |