Much less research has examined intellectual abilities among individuals with lower levels of alcohol exposure, and results have been conflicting. Early studies found moderate levels of prenatal alcohol exposure to be associated with decreases in intelligence scores in young children (Fried & Watkinson, 1988; Streissguth, Barr, & Sampson, 1990; Streissguth, Barr, Sampson, Darby, & Martin, 1989). A more recent study found that moderate alcohol exposure during first and second trimesters significantly affected intellectual ability, but only among African American children (Willford, Leech, & Day, 2006). However, another study reported that moderate levels of consumption are not associated with verbal, performance, or overall IQ scores in childhood (Alati et al., 2008). Although a weak effect of binge drinking (4 or more units of alcohol per occasion) was found, it was attenuated when mother’s educational attainment was taken into account. The discrepancies among studies with lower levels of exposure highlight the need for additional research and importance of considering a variety of factors when evaluating studies.
