The video says incest is legal in new jersey.....
how do you think herds reproduce? some animals chase away all males to keep their harem of females... including their daughters. Incest is a natural animal process.
For humans... it's a bit different as we have more evolved communications and thought processes... still where does incest stop being incest? your sister? your daughter? your cousin? your 2 times remote cousin? It's all a question of the times we live in and in the recent past, even first cousins were considered ok by our societies standards (royal families being a great example)
In a 40 people village, people would marry someone from their village or at most, the next village over... but these were already sons and daughters of people from the 2 villages... so unless you're from a region where there were mass population movements or from larger cities, chances are in your not so distant familly tree, there was some inbreeding to the second or third degree.
on the father daughter though.... that's still creeppy.
OoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoO
