There is something called the Westermark effect. Adults are not sexually attracted to people with whom they grew up. They don't have to be relatives, so we know it's not purely based on pheromones. Some evidence of this is Taiwanese minor marriages, where pairs that were married as children had higher rates of divorce and infidelity and were less likely to have kids. Also Kibbutz age-mates, where Jewish immigrants lived in communal nurseries, and rarely would children that grew up in close proximity marry each other.
Gowantae t1_j0e414u wrote
Reply to comment by Solonotix in What’s With HBO’s Grossest Obsession, Incest? by Sisiwakanamaru
There is something called the Westermark effect. Adults are not sexually attracted to people with whom they grew up. They don't have to be relatives, so we know it's not purely based on pheromones. Some evidence of this is Taiwanese minor marriages, where pairs that were married as children had higher rates of divorce and infidelity and were less likely to have kids. Also Kibbutz age-mates, where Jewish immigrants lived in communal nurseries, and rarely would children that grew up in close proximity marry each other.