The major paradigm of LNG is the study of inter-individual variation and its relation to behavior. The aim is to relate genotype to complex behavioral phenotypes, with the goal of identifying vulnerability and protective alleles responsible for the substantial heritability of alcoholism. To accomplish this, LNG studies intermediate phenotypes which assay functions of neurobiological systems integral to alcoholism and other addictions. These mechanisms include anxiety/stress response, electrophysiological phenotypes, executive cognitive function, behavioral control and reward. Identification of alleles influencing these mechanisms will lead to better understanding of vulnerability, gene-environment interactions, molecular diagnostic markers to individualize treatment, and molecular targets for intervention.