[1] Brigham Young Univ, Psychol Dept, Provo, UT 84062 USA
[2] Brigham Young Univ, 1001 KMBL, Provo, UT 84062 USA
[3] NIAAA, Sect Comparat Behav Genom, NIH, Rockville, MD 20852 USA
[4] NIAAA, Lab Clin Studies, NIH, Bethesda, MD 20892 USA
[5] Eunice Shriver Kennedy Natl Inst Child Hlth & Hum, Sect Comparat Ethol, NIH, Poolesville, MD 20837 USA