There was a study (sorry don't have a link) of children raised in the Israeli kibbutz format and even if not genetically related, children raised in close proximity to each other develop an aversion to intermarriage in their group.
The effect is pronounced in most siblings, but I think it has also been found in anonymous sperm donation children that randomly encounter 1/2 sibling that the effect seems not to occur. There is something about human children being reared and educated in close proximity that seems to put them out of the idea of marrying. (but not always).
Maybe it is a residue of disgust from seeing a sibling diapered, or barfing on the floor, or seeing a tantrum, or peeing the bed, whatever, it puts most of us off for life.
The effect is pronounced in most siblings, but I think it has also been found in anonymous sperm donation children that randomly encounter 1/2 sibling that the effect seems not to occur. There is something about human children being reared and educated in close proximity that seems to put them out of the idea of marrying. (but not always).
Maybe it is a residue of disgust from seeing a sibling diapered, or barfing on the floor, or seeing a tantrum, or peeing the bed, whatever, it puts most of us off for life.
