Abstract
Height variation is known to be determined by both genetic and environmental factors, but a
systematic description of how their influences differ by sex, age and global regions is lacking. We
conducted an individual-based pooled analysis of 45 twin cohorts from 20 countries, including 180,520
paired measurements at ages 1–19 years. The proportion of height variation explained by shared
environmental factors was greatest in early childhood, but these effects remained present until early
adulthood. Accordingly, the relative genetic contribution increased with age and was greatest in
adolescence (up to 0.83 in boys and 0.76 in girls). Comparing geographic-cultural regions (Europe,
North-America and Australia, and East-Asia), genetic variance was greatest in North-America and
Australia and lowest in East-Asia, but the relative proportion of genetic variation was roughly similar
across these regions. Our findings provide further insights into height variation during childhood and
adolescence in populations representing different ethnicities and exposed to different environments.