Meera and Neha are identical twins from a small village in Bihar. When they were two years old, Neha went to live with her aunt's family in Pune, who later adopted her. Meera stayed with her birth parents, who could seldom afford a full meal for the family, and she studied in a village school where one teacher handled five classes. Neha ate well and went to a good city school. At fifteen, both girls took the same intelligence test. Their scores were much closer to each other than those of most pairs of classmates, yet Neha scored clearly higher than Meera.
Which of the following best explains the twins' test scores?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → The closeness of the scores reflects their shared heredity; the gap reflects Neha's richer surroundings later.
Option (1) The closeness of the scores reflects their shared early home; the gap reflects Neha's richer surroundings later. — Incorrect. The twins shared a home only till the age of two, so that cannot keep their scores so close at fifteen. The closeness comes from heredity: identical twins stay alike in intelligence even when they are reared apart.
Option (2) The closeness of the scores reflects their shared early home; the gap reflects inherited differences between them. — Incorrect. This turns the two factors around. Shared heredity keeps the scores close. Inherited differences cannot explain the gap, because identical twins have the same genes.
Option (3) The closeness of the scores reflects their shared heredity; the gap reflects a lower range set by Meera's genes. — Incorrect. Identical twins carry the same genes, so heredity sets the same range for both girls. A lower range for Meera cannot explain the gap. The gap comes from her poorer food and schooling.
Option (4) The closeness of the scores reflects their shared heredity; the gap reflects Neha's richer surroundings later. — Correct. Identical twins have the same heredity, so their scores stay close even when they grow up apart. Heredity sets a range, and the support and opportunities of the environment decide where a person falls within it. Good food and schooling raised Neha's score, while deprivation lowered Meera's.
NCERT (2026-27): “Intelligence: Interplay of Nature and Nurture “With respect to the role of environment, studies have reported that as children grow in age, their intelligence level tends to move closer to that of their adoptive parents. Children from disadvantaged homes adopted into families with higher socioeconomic status exhibit a large increase in their intelligence scores. There is evidence that environmental deprivation lowers intelligence while rich nutrition, good family background, and quality schooling increases intelligence. There is a general consensus among psychologists that intelligence is a product of complex interaction of heredity (nature) and environment (nurture). Heredity can best be viewed as something that sets a range within which an individual’s development is actually shaped by the support and opportunities of the environment.” |