“…Longitudinal as well as cross-sectional studies have shown variations with age in heritability estimates from infancy to adulthood, even though the patterns of variation are not completely clear (Haworth et al, 2008;Heude et al, 2005;Lajunen et al, 2009;Rebato et al, 1997Rebato et al, , 2005Salces et al, 2009;Silventoinen et al, 2007Silventoinen et al, , 2008. In general, as in the present study (data not shown), the agepattern of genetic contribution estimates demonstrates a gradually increasing impact of the child's genotype Ulijaszek and Mascie-Taylor, 1994).…”