Family size and sibling position as related to measured intelligence and academic achievement.

Abstract

1359 14-17 year old male high school students studying in 22 urban and 6 rural secondary schools in the Lucknow district of India were randomly selected to test the relationship if any between family size and sibling position and measured intelligence and academic achievement. The Progressive Matrices Test was administered as an untimed capacity test. Raw scores were used since norms for Indian students were not available. Marks in the high school examination were used as evidence of academic achievement. There was a significant gradual decline in the mean intelligence test scores and mean high school marks as family size increased (p less than .01). The differences in academic achievement were still significant even when measured intelligence was held constant (p less than .01). Sibling position did not have a consistent relationship either with intelligence test scores or academic achievement although third-born children were first in academic achievement and those sixth-born or later were inferior to all other groups.