Disgust is about rejection: rejection of what might be contaminated or might be distasteful, either physically or psychologically. At its basic level it seems to occur without cognition, although of course we also learn to be disgusted at many things. From a differential emotions perspective, Izard (1991) discusses disgust as fundamentally related to the expulsion of contaminated food, the experience of which only develops when the cognitions necessary to appreciate/understand it have developed. Usually associated with disgust is contempt (characterized by Tomkins, 1963, as dismell - compare the facial expressions of the two emotions), which, as Izard puts it, is ". . . associated with feelings of superiority" (1991, p. 279). He characterizes it as a truly negative emotion, predominating as it does in a range of endeavours from prejudice to murder.
In a cogent analysis, Rozin, Haidt and McCauley (1993) describe disgust as one of a few uniquely human emotions. They argue that, assuming that there are basic emotions, then it is clear that disgust should be included among their number, viewing it as similar to guilt, shame and embarrassment (see later). They see disgust as satisfying Ekman's (1992) criteria for emotions - it has a universal signal, comparable expression in lower animals, a specific physiology, universal preceding events, a coherent response system, a rapidons et, a brief duration, an automatic appraisal mechanism and an unbidden occurrence.
After discussing various ways of looking at disgust, Rozin et al. conclude that its cultural evolution suggests that it is concerned with essential humanness. Clearly, disgust began (in evolutionary history) as a very useful rejection of bad or contaminated tastes. But it has developed in humans far beyond this to a much more abstract type of rejection of potential foods, with a particular concern with body products. They consider that a fear of animal products and mortality and their associated decay has replaced the original condition of the more simple avoidance of bad taste. Jones (2000) takes the argument further, making the point that, although disgust appears to be universal, it does not seem to be innate, in that, for example, many young children will put almost anything into their mouths, to their parents' consternation. Jones also argues that since disgust is clearly bound up with taste and that taste is considerably broader than a purely gustatory matter, then disgust is also associated with aesthetics and moral judgements. To some extent, a similar argument can be made about all the specific emotions; they are partly concerned with the moral order.
