Genetic Sexual Attraction: Urban legend or ticking time bomb? from Confessions of a Cryo-kid.
Why taking biology out of family isn't a good idea for the long term.

"Often, the attraction isn't sexual, but it's still frightening and alien, and therefore perceived as abnormal and sinful. One woman told me that she and her birth mother, soon after they met, slept together in the nude: there was no sex, only a strong need to be close as parent and child. Grown men tell me they've sat in their mother's lap, just being rocked and held. One man talked about his need to be sexual with his newly found brother, but not being homosexual they shared a woman instead" (Genetic Sexual Attraction, The Guardian, May 17, 2003).
I think it’s about time that people begin to realize that this is an actual reality and that the consequences are beyond what we can imagine. We’re not just worried about half-siblings meeting, but what about cousins and other degrees of consanguinity?? And while birth defects due to increased degrees of consanguinity are still low, take a look at the risks on a larger scale

Interesting. Why do we put up with behavior in blood relatives, that we would never tolerate in someone else? I remember visiting the extended in-laws one holiday, all the adults that married into the family shook our heads in disbelief at their behavior, yet if it was 'our' family we would be treating each other in the same dysfunctional way. That's why they are called 'in-laws', they are distinctively acknowledged to be different then blood relatives and should be treated this way.
A person doesn't expect their mother-in-law to treat him/her the same way s/he treats her own children. It isn't family, with the same bonds created through parental lineage or sibling connections. We talk about genetics as being taboo in terms of mating, that our body is to respond negatively to incestuous relationships, but our genes respond to sanguine bonds in positive ways to tolerate behavior we wouldn't with strangers(in-laws).

I listed this under third party-procreation, since 'Cryo-kid' was conceived by donor', but I see the bigger issue with men and women having children with the ripple effect of the break down of marriage. I wrote about here "strangers among us"

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