Vol. 11, Special Issue 6 (2022)

Author(s):
Annu and Bimla Dhanda

Abstract:
Individual differences in intellectual abilities are highly heritable in the early childhood. Twin investigation has supported the concept of intellectual abilities by showing the genetic and environmental contributions on intelligence of twins. The contribution of genetic architecture was ranging from 50-67% in the variations of intellectual abilities of twins in early years of life. The sample size for present study comprised of 150 pairs of twins with the age group 3-6 years from two districts, namely: Bhiwani (N = 174) and Hisar (N = 126) of Haryana State. The contribution of genetic and environmental factors was examined in twin study design. The intellectual abilities of twins were measured using the Stanford Binet Intelligence Scale (Terman and Merrill, 1960) ^[10]. Language stimulation and physical environment aspects of home environment was measured by using the Home Observation for Measurement of the Environment (HOME) (Caldwell and Bradley, 1984). Heritability estimate was used to examine the genes contributed to shape the intellectual abilities of twins in early years of life. The result of heritability estimates revealed that the heritability estimates of intellectual abilities was from 50 percent to 67 percent from the age group 3-6 years. The findings clearly elucidated that the intellectual abilities were more influenced by genetic architecture than the environmental factors during early childhood period. The monozygotic twins were more correlated in their intellectual abilities than the dizygotic twins. The home environmental aspects were also significantly associated with intellectual abilities of twins in early years.