Shared environmental sources of the variation in nonverbal intelligence are largely twin-specific: the study of twin and sibling pairs from Russia,

Voronin, I.; Malykh, S.; Tikhomirova, T.

Авторы: Voronin I., Malykh S., Tikhomirova T.
Журнал: Behavior Genetics
Том: 48
Год издания: 2018
Издательство: Springer Nature
Местоположение издательства: Switzerland
Первая страница: 519
DOI: 10.1007/s10519-018-9929-8
Аннотация: Our previous research on Russian adolescent twins revealed a substantial shared environmental variation in the individual differences in the non-verbal ability (65%, Malykh et al. 2016), unlike the other behavior genetic research of cognitive abilities (30%, Polderman et al. 2015). The current study aimed to estimate the role of twin-specific shared environmental effects by comparing twin and sibling pairs. The sample included 730 twin pairs (305 MZ, 425 DZ, mean age 13 years, SD = 2.9 years) and 154 sibling pairs (139 full sibling, 15 half sibling, mean age 11 years, SD = 3.2 years). The mean age difference in sibling pairs was 4.4 years. The non-verbal ability was assessed by means of Raven’s Progressive Matrices. The twin-sibling model included the age variable to filter out the age-related variation. The MZ and DZ twins showed substantially higher similarity in cognitive ability than full and half siblings (r = 0.78 and 0.67 versus 0.20 and 0.23) which indexes the twin-specific shared environment. The total estimate of the shared environmental effects was 73%, the rest of the phenotypic variance accounted for non-shared environment (27%). Half of the shared environmental variance was twin-specific (34% of the total variance). The age had statistically significant effect in the twin-sibling model (b = 1.36, p\0.05). Our results suggest that the large part of the shared environmental effects of the non-verbal intelligence is twin-specific. This matches the twin-sibling research on the child twins (Koeppen-Schomerus et al. 2003). We suggest that the twin-specific environmental effects observed in our study stem from the school environment. Unlike siblings, twins undergo the school program synchronically and often attend the same class. Therefore the twins share more environmental variation than siblings. As an additional analysis we computed the similarity in the two groups of full siblings divided by the median age difference 4 years. The siblings with closer age exhibited higher similarity in the level of cognitive ability than the siblings of dissimilar age (r = 0.44 and - 0.07)
Добавил в систему: Малых Сергей Борисович

	ИСТИНА	Войти в систему Регистрация
	ИПМех РАН
	Главная Поиск Статистика О проекте Помощь

ИСТИНА

ИПМех РАН

Shared environmental sources of the variation in nonverbal intelligence are largely twin-specific: the study of twin and sibling pairs from Russia,статья