Argument: Children of incest are at greater risk of disorders
Johann Hari. "Forbidden love". Guardian. January 9, 2002 - So why is your stomach still churning as you read this? What is it about incest that makes it universally abhorred? The most obvious answer is the risk of producing severely deformed children. King Hatchepsut, an Egyptian pharaoh who was the product of an incestuous union between brother and sister, is considered by many Egyptologists to have suffered from birth defects. In Michigan in the mid-1990s, the state laws had to be reformulated to forbid "consensual incest" after two high-profile scandals. In both cases, the offspring of father-daughter relations had severe birth defects and several of the resulting babies died. All existing studies of inbred populations show that incest increases the rate of appearance of negative recessive genes.
A German High Court called The Karlsruhe court ruled in 2008 in favor of its existing laws on incest, arguing, "the prevention of grave genetic disease in the offspring of incestuous relationships."
The German Federal Constitutional Court ruled in a 2008 incest case that incestuous relations, "have an effect on family and society, and have consequences for children who arise from the relationship."
Miranda Devine. "Crossing the Line". The Sun Herald (Australia). April 18, 2008 - ACCORDING to 60 Minutes, John and Jennifer Deaves and kids appear to be "the picture-perfect family". Except they are father, 61, and daughter, 39, who "live together as a couple in every sense of the word", as the program so tastefully put it last Sunday.
Jennifer has borne her father two children, one who died of congenital defects a few days after birth, one who survived "blissfully happy and perfectly healthy", according to the program, which somehow managed to neglect any mention of the dead child.
Genetic disasters are a good reason for the taboo on incest, which 60 Minutes treated as some sort of antiquated hindrance to irresistible sexual attraction between two consenting adults.