The most immediate reason for the social prohibition of incestuous relationships is biological. Human genetic diversity is a survival mechanism.
Every human carries hidden genetic mutations. In unrelated pairs, these rarely overlap.
If you are interested in a more specific angle, I can help you explore: The most immediate reason for the social prohibition
Provides clarity on the regulations regarding domestic relationships in your specific region.
Some psychologists suggest that the lack of "Westermarck effect" (a natural desensitization to family members grown up with) leads to confusion when reunited. In unrelated pairs, these rarely overlap
The and how humans naturally develop "mating aversions."
In modern social topics, researchers sometimes discuss . This is a controversial theory regarding people who were separated at birth and meet as adults. The and how humans naturally develop "mating aversions
Often, what is perceived as "romance" in these niche online topics is actually a manifestation of deep-seated trauma or abandonment issues.