Are sibling relationships legal?

In the United States, incest laws prohibited intimate relationships between children and parents, siblings, and grandchildren and grandparents. Almost all states criminalize incest between adults. Some states also prohibit intimate relations between aunts, uncles, nieces, nephews, and cousins.

Is incest a crime?

Sexual relations between family members who are not spouses, formally known as incest, is illegal across the U.S. because of the harm that it can cause to family relationships. Incest often can be charged as a violation of a different law, such as child abuse, child molestation, rape, or statutory rape.

Why is inbred bad?

Inbreeding results in homozygosity, which can increase the chances of offspring being affected by deleterious or recessive traits. This usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce.