The purpose of the current study was to explore the genetic and environmental association between working memory and different behavioral aspects of the attention network (i.e., executive attention, alerting attention, and orienting attention), using a twin design. Data were from 131 monozygotic (39% male) and 173 same-sex dizygotic (44% male) twins. Individual differences in working memory performance and behavioral measures of executive attention, alerting attention, and orienting attention were found to be moderately heritable. A modest nonshared environmental effect was found for all variables. Individual differences in working memory were significantly correlated with variability in executive and alerting attention, but not orienting attention. All of the association between working memory and executive as well as alerting attention was statistically mediated by genetic influences, indicating a common genetic mechanism or mechanisms underlying the links between working memory and certain behavioral indicators of attention. / Master of Science