1. Ainslie, R. C. (1985) The Psychology of Twinship. Lincoln: University of Nebraska Press.
2. Alberts-Corush, J., Firestone, P., and Goodman, J. T. (1986) Attention and impulsivity characteristics of the biological and adoptive parents of hyperactive and normal control children, American Journal of Orthopsychiatry 56, 413–23.
3. Alford, J. R., Funk, C. L., and Hibbing, J. R. (2005) Are political orientations genetically transmitted? American Political Science Review 99, 153–67.
4. American Psychiatric Association (2000) Diagnostic and Statistical Manual of Mental Disorders, 4th edn, text revision. Washington, DC: American Psychiatric Association.
5. Arcos-Burgos, M., Castellanos, F. X., Pineda, D., Lopera, F., Palacio, J. D., Palacio, J. D., Rapoport, J. L., Berg, K., Bailey-Wilson, J. E., and Muenke, M. (2004) Attention-deficit/hyperactivity disorder in a population isolate: Linkage to loci at 4q13.2, 5q33.3, 11q22, and 17p11, American Journal of Human Genetics 75, 998–1014.