Scientists Are Trying to Find Out. Studies of identical and fraternal twins have long been used to untangle the influences of genes and the environment on particular traits. Over the course of 20 years, they studied pairs of twins — 81 pairs of identical twins twins who developed from one egg that split in twoand 56 pairs of fraternal twins twins who developed from two eggs fertilized by two different sperm. Another study found that happiness and well-being had a 50 percent genetic influence. The Minnesota researchers found that about 70 percent of IQ variation across the twin population was due to genetic differences among people, and 30 percent was due to environmental differences. Born together, raised apart Researchers at the University of Minnesota, led by Thomas Bouchard, launched the landmark study in
The culprit for the odd similarities?
Twins Separated at Birth Reveal Staggering Influence of Genetics
Another study of four pairs of twins found that genetics had a stronger influence on sexual orientation in male twins than in female twins. The Landmark Minnesota Twins Study" Harvard University Press,is now doing a prospective study of Chinese twins raised apart, often in different countries, by adoptive families. Among identical twins, 80 percent of those surveyed reported feeling closer and more familiar with their twin than they did to their best friends, suggesting a strong genetic component in the bond between identical twins. One of the newer twin registries to come online, the Michigan State University Twin Registry MSUTR was founded in to study genetic and environmental influences on a wide range of psychiatric and medical disorders. The scientists found that genetics accounted for only 35 percent of the differences between identical and fraternal gay men and even less—roughly 18 percent—in gay women. Turkheimer noticed that most of the studies that found I. Who is the New Jamestown Skeleton?