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A professor at Columbia has been charged with having an incestuous relationship with his adult daughter.
Leaving aside the issue of whether closely related people should have babies, should this be a crime?
Actually an issue i looked into a while ago in regards to the man who married his grandmother.
It is a tricky situation, unlike what 3body is saying age of consent is not the sole issue in this case. A parent and child have a very different relationship than most sets of people. For at least (around) the first 18 years of life a child has to learn to take the advice of, and follow the instructions of their parent. If someone was interested in this kind of relationship , it would be rather easy to groom the child during these 18 years in order to do so. Thereby, from a practical standpoint taking away the persons ability to chose come adulthood.
If someone can be raised to believe that they should avoid getting a blood transfusion, there is no reason the same type of brain washing cannot be used in order to convince them that a sexual relationship with a parent is preferable to one with someone not within the family.
Then there is the issue of consequences, which is also a special case. Parents have a lot they can take away from their children, and i am not just speaking of when the children are underage. If the father wants to have a sexual relationship and the daughter does not ( and lets say, just to make it interesting, that it is not because it is incest, but the daughter simply doesn't find him attractive. ) , he has a lot of leverage to use to get it. Anything from simple non communication, to outright hostility could be an option. And unlike a non incest based relationship , this is family. While a girl may be able to tell me to **** off and never want to see me again, this is different for a father, this is someone, who one would want a lasting and in depth relationship.
The effects of incest also should be mentioned, while there is some evidence that for a few generations this will be minimal, if the practice is kept up, they are predisposing their children/grandchildren to more genetic flaws.
And finally, and perhaps a bit more ethereally, there is the issue of, " When did this man decide he found his daughter attractive?". A parent is expected to take pretty intimate care of a child, bathing them, etc. At what point can we say that if someone is attracted to their child , it is wrong for them to be seeing them naked? The man very well may have never touched her in a sexual manner until adulthood, but there is a strange line in which he very well may be thinking at age 14 or so " i would like to have sex with her. " , and now that you take away the Platonic love of a parent and replace it with the sexual love of a lover, ( regardless of if this is acted upon. ) you have a pedophile with access to his ( or her) own personal, perfectly legal stash of child porn.
So what we have, is the ability to brainwash a child to agree with having sex with you ( even if it is only in adulthood. Which, i believe a case could be made, that in most cases like this it is not. ) , the ability to hold a stable family unit as punishment for non compliance, and an easy way for someone who wants to view underage people naked to do so. All in all, entirely too many ways that a child can not have a choice in the matter. For the good of the child, yes i do believe a blanket law banning incest especially between a custodial parent and child is appropriate.