Paul Rozin's Research and Teaching at Pennsylvania University about disgustion reasons

The characteristic grimace, nausea, and avoidance of the repulsive object is an innate reaction to the questionable taste of the food consumed. Meanwhile, people turn their faces not only at the taste but also at the idea of coming into contact with an unwanted substance. According to psychologist Professor Paul Rozin of the University of Pennsylvania, the conception of the disgust response is an evolutionarily acquired defense mechanism against expanding environmental contamination.