Incest is not only illegal, it is an international taboo. The primary excuse for creating incest laws was, and is, the frequency of genetic defects both physical & mental. Those wishing to legalize incest between consenting adults claim modern technology can correct or limit many birth defects, as well as diagnose them early enough to abort and try again. But this was not only reason societies created the incest taboo.Even our ancients realized that there is a deeply emotional, power dynamic that exists between the nuclear family(Mother-son, Father-Daughter & opposite sex siblings). Even in ancient times when males owned their families like property these cultures recognized the societal need to protect the family unit by defining it's boundaries. A person does not stop being THE parent when their child turns 18. A daughter or son still has the desire share & feel the parental bond even as adults but they will never be psychological equals ( consenting adults) with their parents. The incest taboo was spread throughout the world to protect children of any age from the lust & ownership of their parents.
Today psychologists recognize this psycho-sexual syndrome as Genetic Sexual Attraction. It is an obsessive need to be with a family member. This syndrome has been documented by many adoption agencies as effecting almost 1/2 of adopted adults who search out & find their biological family members. The genetic similarities of appearance & smell of their immediate family members, compounded with the desire to share familia bonding, can trigger a feeling of "Love at first sight". Not knowing how to deal with these loving feelings as a traditional family the relationship becomes sexual. This can be heterosexual or homosexual(Father & son, same-sex siblings, etc...). The desire to never again be parted, turns a family reunion into an unintended incestuous relationship that often rips apart the previous family relationships of these adults. When meeting their lost relative for the first time they all claim they experienced "an overwhelming and complicated rush of emotions" and an "almost irresistible sense of falling in love." They all said they had a need to discover an unusual form of closeness and intimacy with their relative, who had felt the same way. But should we consider these obsessed people to be "consenting adults" under the law?
A parent always holds the psychological power over their offspring regardless of age. That is why many of us were repulsed when we learned Woody Allen was having sex with the 18 yr old daughter of his mistress, Mia Farrow. Allen had been this girl's surrogate Father-figure for 9 yrs. They weren't related by blood but yet in the minds of many there was the question if this was actually consensual or psychological manipulation. When the actress McKenzie Phillips revealed her adult sexual relationship with her estranged biological Father, it again opened the debate about incest laws. But again one has to wonder about the motives of a Father who started his own daughter on drugs as a young teen. Could she really be considered a "consenting adult" in that relationship at age 18?
Freud argued that the reason we prohibit incest is that we are so powerfully tempted by it. That's why it's taboo, not just illegal. We have to erect barriers of horror and disgust to prevent ourselves from succumbing to temptation.
That has to be part of the argument. Children need to be protected from sexual exploitation by parents, because it is all too easy for them to be abused. Parents are strong and lustful, but children are weak and vulnerable. Age does not diminish this dynamic. And we know all too well the life-long damaging effects on children who are exploited by those on whom they are dependent. Their capacity to trust others is impaired if not destroyed.
So we need laws and customs and taboos - whatever it takes -- to preserve the trust that even adult-children need to have in their parents. That trust is not only the basis for their future relationships with others. It's the basis for the confidence they need to be responsible adults and citizens.
