Inbreeding is the production of offspring from the mating of individuals who are closely related. Inbreeding is taboo worldwide due to the high potential for sexual abuse, especially child abuse, and lasting trauma. Additionally, the chances of inheriting genetic disease significantly increase among children who are the result of inbreeding.
Researchers from the University of Queensland observed 450,000 genomes from people of European descent born between 1938 and 1967. Out of the group, 125 people met the inbreeding criteria, meaning the parents were either first-degree relatives (siblings) or second-degree relatives (aunts, uncles, etc.). In this group, researchers found common health issues such as decreased cognitive abilities and muscular function, reduced height and lung function, and a greater risk of contracting diseases in general.
While inbreeding is incredibly taboo in the United States, it is somewhat legal in some states. While not widely practiced, first-cousin marriage is legal in 19 states, and some first-cousin marriages are legal in six states. Sexual relations and cohabitation are only prohibited in nine states. Approximately 0.2% of all marriages in the United States are between second cousins or closer. That means that there are about 250,000 Americans that are in these relationships.
Inbreeding is more common in the following states: Washington, Oregon, Montana, South Dakota, New Mexico, Oklahoma, Arkansas, Louisiana, Indiana, Kentucky, Tennessee, Alabama, Georgia, South Carolina, North Carolina, Virginia, West Virginia, Maryland, Delaware, and Maine. Generally, inbreeding is more common in the southeast region of the U.S. and more rural states. Approximately 70% of inbred families live in desolate areas.
Inbreeding is common, specifically, in the eastern part of Kentucky, and the region is plagued by the stereotype that every family is an inbred family. While the stereotype is not entirely true, inbreeding rates are higher in eastern Kentucky than in any other part of the state. It is believed that this is partially because people have moved to the mountains in eastern Kentucky for the low cost of living and the lifestyle. Still, there are typically no other families living in these locations. The families that move there either don’t have the money to leave or do not want to leave, and the growing children typically inbreed to save their family name.
One family from Kentucky known for generations of inbreeding is the Fugate family. The Fugate family was relatively isolated from the rest of society for nearly 200 years. Their inbreeding led to several medical problems and recessive genes being passed down through each child, such as one that gave some of the offspring blue skin. The blue skin gene is a recessive gene that only appears when both parents are carriers of the gene. The inbreeding caused the recessive gene to appear in both parents.