Why wasn't incest looked down upon back then?

When and why did people start looking down upon incest?

>>2862988

I don't have an answer, but it doesn't even have to be written down as an aberration for one to be repulsed by it

>>2863002
why are you repulsed by it? It doesn't harm anyone

File: 1448169315290-1.jpg (78KB, 780x585px) Image search: [Google]

78KB, 780x585px

>>2863335
There's a family of retards down the street from my house. a while ago I learned from my weed dealer that they all fuck each other and that's why they're all retarded. Whenever I see them I'm very uncomfortable.

Is it normal for cousins to find each other attractive?

>>2864123
>my weed dealer
Opinion disregarded.

>>2864129
cousin fucking probably isn't nearly as bad as parent/child fucking. that's what my retarded neighbors do and apparently have been for several generations.
>>2864132
don't worry, he's white.

One of my best friends for a while was a product of brother sister incest. He was actually really smart, but was just a piece of shit.

>>2864129
Cousins have been fucking eachother since the dawn of time