(R. E. Gur and Gur 1990; R. C. Gur et al. 1995; R. C. Gur et al. 2000; Speck et al. 2000; Weiss et al. 2003; Bell et al. 2006). However, sexual dimorphism of brain measurements in adults can be biased by multiple factors, such as environment and most obviously height differences (Dekaban 1978; Fausto-Sterling and Balaban 1993). Cumulative mean height within the first 15 years of life varies by only 1% between boys and girls, and girls are taller from 10 to 13.5 years old (Kuczmarski et al. 2002). Therefore, studying sexual dimorphism on brain measures across the age span from birth to young adulthood has the advantage of identifying factors that could influence gender-specific differences, and when (e.g., perinatal, childhood, adolescence) and why (e.g., gene specific, hormonal, environmental) these differences arise. This section provides a comprehensive review on how structural and functional neuroimaging deciphers genetic-by-gender-by-age interactions on the developing brain.
