乱伦属于文化现象，不同的文化圈，理解不同。

美国有些州表兄妹结婚合法，比如阿拉巴马，有些州就是违法乱伦。其他州就嘲笑阿拉巴马人乱伦。

在世界上，有十个国家乱伦合法：Places

like Israel, Argentina, Brazil, India, Ivory Coast, Japan, Latvia, South Korea, Turkey, and

Thailand allow incest without legal repercussions if each person is a consenting adult of a certain

age.

有专门的研究：Understanding the Taboo of Incest in the American

South through Analysis of Southern Gothic Literature ；

DEFINING RELATEDNESS WHILE CROSSING STATE LINES: CHANGES IN THE

AMERICAN CULTURAL CONSTRUCTION OF INCEST

等等