Infant social inhibition is associated with increased risk for anxiety later in life. Although both genetic and environmental factors are associated with anxiety, little empirical work has addressed how developing regulatory abilities work with genetic and environmental risk to exacerbate or mitigate problem behaviors. The current study was aimed at addressing this gap in research by investigating an early emerging regulatory behavior, attention control, in association with genetic and environmental risk for anxiety. Participants included 9-month-old adopted infants, their birth mothers, and adoptive parents (N = 361). Lifetime diagnosis of birth mother social phobia was obtained using structured interviews. Adoptive parents completed self-report measures of anxiety symptoms. Infant social inhibition and attention control were coded during a stranger interaction and a barrier task, respectively. Neither adoptive nor birth parent anxiety was directly associated with social inhibition. The association of attention control with social inhibition in infants was moderated by birth and adoptive parent anxiety symptoms. When infants of birth mothers with social phobia were raised by adoptive parents with high self-reported anxiety symptoms, greater attention control was associated with greater social inhibition. However, when raised by adoptive parents with low self-reported anxiety, greater attention control was associated with less social inhibition. (Contains 1 figure, 3 tables, and 1 footnote.)