Final answer:
The disgust and revulsion towards incest is a cultural response, reinforced by the universal incest taboo, religious beliefs, and social norms that dictate and regulate sexual behavior to maintain social coherence.
Step-by-step explanation:
The disgust and revulsion that most people feel regarding the topic of incest can be understood as a societal reaction fostered by the incest taboo, a universal cultural norm designed to prohibit sexual relationships between closely related individuals, such as parents and their offspring. This taboo extends to varying degrees relative to each culture's definition of which familial relations are considered too close for sexual relationships. Sociologists and anthropologists affirm that the incest taboo is present in every society, though it varies in its definitions of prohibited relationships. Freud even suggested that such taboos were linked to deeper psychological processes.
Negative attitudes towards incest are rooted in a combination of this taboo, as well as the moral, ethical, and often legal implications surrounding such relationships. Additionally, these attitudes are reinforced by religious and cultural norms that dictate sexual behavior and social structures. It is evident that such emotional reactions as disgust and revulsion to incest are deeply ingrained cultural responses, which serve to reinforce social coherence and prevent biological and social issues associated with incestuous relationships.