WASHINGTON (Sinclair Broadcast Group) -- A research study done over seven years by a data scientist at Columbia University shows that it is okay to marry your first cousin as long as your children do not marry their first cousins, according to Popular Science.
The paper, which was published in the Science journal, is based on a 13 million member family tree and looks at data that was found in online genealogy profiles.
According to estimates, 4 to 7 percent of the children from first cousins are likely to have birth defects. In comparison, 3 to 4 percent of the children with distantly related parents are likely to have defects.
It is also believed that first cousins share 12.5 percent of their DNA. Second cousins share 6.25 percent of DNA while third cousins share 3 percent.
The percentage increases more if the offspring of first cousins marry another first cousin. This also makes that offspring more susceptible to certain diseases that their mom and dad are both predisposed to.
The study also discovered that from 1650 to 1850, the average person was a fourth cousin to their spouse. In 1950, the average person was the seventh cousin to their spouse. The research believes today, humans are 10th to 12th cousins away from each other.
Many states began to ban cousin marriages after the Civil War. In 2018, 24 states have continued the cousin marriage ban but there are still at least 20 states where the ban does not exist.