The Center for Study of Multiple Birth
333 E Superior St, Ste 464
Chicago, IL 60611
International Society for Twin Studies
The International Society for Twin Studies (ISTS) is an international, nonpolitical, nonprofit, multidisciplinary scientific organization. Its purpose is to further research and public education in all fields related to twins and twin studies, for the mutual benefit of twins and their families and of scientific research in general. The society was founded in Rome in 1974.
Professor Nicholas Martin
Queensland Institute of Medical Research
Post Office, Royal Brisbane Hospital
Brisbane, QLD 4029 Australia
Facts About Multiples
An online encyclopedia of multiple births.
University of Minnesota-Twin Cities
The Minnesota Twin Family Study seeks to identify the genetic and environmental influences on the development of psychological traits.
University of Southern California
The Southern California Twin Project at USC was established to research the roles of heredity (genes) and environment (culture) in producing individual differences in human behavior. Topics of investigation include personality, cognitive abilities, mate selection, antisocial behavior and delinquency.
University/Medical College of Virginia contains the Mid Atlantic Twin Registry with over 12,000 sets of twins. This site provides twin research results for current VCU studies. http://www.matr.vcu.edu/us2.htm 
King's College London
The United Medical and Dental School of St. Thomas' Hospital, part of King's College London, has been conducting research on twins over the age of 18 since 1992. Research is currently being conducted on bipolar disorder and schizophrenia. http://www.iop.kcl.ac.uk/departments/?locator=557 
First Candle/SIDS Alliance Inc.
The First Candle/SIDS Alliance is a private nonprofit 501(c)(3) organization that funds research for Sudden Infant Death Syndrome (SIDS). Additional goals of the organization include creating service delivery systems to better serve families and providing support programs for public education and awareness.
1314 Bedford Ave, Ste 210
Baltimore, MD 21208
(800) 221-7437 or (410) 964-8000