Louisville Twin Study, Child Development Unit, Department of Pediatrics, Health Sciences Center, University of Louisville, Louisville, Kentucky
Address for reprints: Marilyn L. Riese, Ph.D., Louisville Twin Study, Child Development Unit, Department of Pediatrics, Health Sciences Center, University of Louisville, Louisville, KY 40292; e-mail: [email protected]; fax: 502-852-1093.
Acknowledgments. This research was supported in part by a grant from the John D. and Catherine T. MacArthur Foundation and by Grants HD-14352 and HD-22637 from the National Institute of Child Health and Human Development. The author is grateful to the parents and their infants who participated in the study; to the administrators and nursing staffs in the participating hospitals; and to L. J. Goldsmith, E. Harpring; M. Hinkle, A. P. Matheny, Jr., P. McNulty, B. Moss, P. Murphy, S. Nuss, M. Riedesel, and K. Sears for their contributions.