When ‘Yuck’ Isn’t Enough: Rethinking Disgust and Morality with Dr. Daniel Kelly

When I picked up Dr. Daniel Kelly’s Yuck! The Nature and Moral Significance of Disgust, I thought I was in for a straightforward discussion of why certain things make us recoil, the sight of spoiled food, the smell of decay, or the feel of something slimy. But the book turned out to be a far richer and more thought-provoking exploration. It didn’t just dwell on the bodily origins of disgust; it pushed me to reflect on how this emotion has seeped into our social and moral lives, often with troubling consequences. Reading it was like holding up a mirror to my own reactions, moments when I have said “that’s disgusting” without stopping to ask why, and whether such a judgment really had any moral weight.

One of the first things I appreciated about Dr. Kelly’s approach is his insistence that disgust is not a simple reflex. It is not just about gagging at a bad smell. He builds a cognitive model that highlights disgust as a signaling system, an evolved mechanism designed to protect us from harmful substances like poisons, parasites, and pathogens. I found this framing persuasive. It made sense that disgust, at its evolutionary core, is about survival. The feeling of revulsion acts like an alarm, steering us away from what could harm our bodies before our rational mind has time to calculate the risk.

But Professor Kelly doesn’t stop there. He goes on to trace how this once-practical system has been co-opted to govern not only our physical interactions but also our social and moral judgments. I found myself pausing at his examples of how people use disgust to evaluate not just foods or bodily substances but also behaviors, lifestyles, and even entire ideologies. This was where the book began to feel uncomfortably relevant. I could think of times when I have heard people dismiss others’ practices or identities with a simple “gross,” as if that reaction alone were sufficient reason for condemnation. Professor Kelly challenges that assumption, showing that moral disgust is often a misfiring of an old biological system applied to domains it was never designed for.

What struck me most was his warning against using disgust as a tool for moral justification. Throughout the book, Professor Kelly makes the case that disgust is not a reliable guide to what is right or wrong. This resonated with me deeply. I thought of historical examples where disgust has been marshaled to justify oppression, racist depictions of certain groups as dirty or disease-ridden, or the stigmatization of non-normative sexualities under the guise of moral repugnance. Dr. Kelly’s analysis made me realize how dangerous it can be to equate a visceral emotional response with a moral truth. Just because something makes me feel sickened does not mean it is ethically objectionable.

At the same time, I found myself reflecting on the tension between the universality and variability of disgust. Kelly emphasizes that while the core function of disgust is universal - protecting us from contaminants, the triggers for disgust vary widely across individuals and cultures. I could see this in my own experiences: foods that I consider revolting are delicacies elsewhere, and practices I take for granted might be off-putting to others. Professor Kelly’s point here is humbling. It forces me to see disgust not as an objective measure but as a culturally shaped lens. What one society encodes as “unclean” or “abhorrent” might have no such meaning in another.

One of the most eye-opening sections for me was Dr. Kelly’s exploration of the expressive dimension of disgust. He argues that disgust functions as part of an automatic signaling system. When I wrinkle my nose or pull back in revulsion, I am not just experiencing disgust privately; I am broadcasting a message to others around me - “avoid this!” That insight made me reconsider how contagious disgust can be. I recalled instances where a group’s collective reaction amplified my own sense of revulsion, even when I wasn’t initially bothered. Professor Kelly’s framing helped me see disgust as a socially coordinated mechanism, not just an individual response.

Yet the very efficiency of this signaling system is what makes disgust so morally precarious. Because it bypasses rational deliberation, disgust can spread rapidly and shape judgments without scrutiny. Dr. Kelly notes that this is why disgust has been a powerful rhetorical tool in politics and culture wars. Once something or someone is branded as disgusting, the label can stick, shutting down further dialogue. Reading this, I found myself uneasy. I thought of how easily “yuck” has been weaponized in debates about immigration, sexuality, or public health. Dr. Kelly’s book sharpened my awareness of how such moves exploit a deep-seated emotion for divisive ends.

As much as Professor Kelly critiques the moral misuse of disgust, he doesn’t deny that the emotion remains a vital part of our psychological repertoire. I admired his balanced stance. He acknowledges that disgust continues to play a protective role in guiding us away from genuine hazards, especially in environments where not every danger can be consciously identified. At the same time, he urges us to resist granting disgust the authority to decide moral questions. That distinction between using disgust as a survival instinct and using it as a moral compass -was, for me, the central takeaway of the book.

Reading Yuck! also made me reflect on my own habits of thought. I realized how often I let disgust act as shorthand for moral disagreement. If I find a practice revolting, it is tempting to leap to the conclusion that it is wrong. Dr. Kelly’s arguments reminded me to interrogate that leap, to ask whether my response is grounded in reasoned ethical principles or simply in the quirks of my evolved biology and cultural conditioning. This, I think, is the book’s real gift: it trains me to pause, to separate my gut reaction from my considered judgment.

By the time I finished Yuck!, I felt both enlightened and unsettled. Enlightened, because I now had a clearer understanding of disgust’s evolutionary roots, cognitive structure, and social dynamics. Unsettled, because I had to confront the possibility that some of my moral intuitions might be less reliable than I thought. Professor Kelly does not leave the reader in despair, though. His work suggests that by recognizing the limits of disgust, we can cultivate a more reflective and compassionate moral outlook. We can learn to see “yuck” not as a final verdict but as a starting point for inquiry.

In sum, Dr. Daniel Kelly’s Yuck! is more than a study of a single emotion. It is a window into how our biology shapes our culture and how our culture, in turn, reshapes our moral landscape. For me, it was a reminder that the feelings I take for granted are not infallible guides but complex legacies of evolution and society. The next time I feel disgust rising in me, I hope I will remember Kelly’s lesson: that my reaction, while real, is not the same as a moral truth. And in that pause, perhaps, lies the possibility of a more just and thoughtful way of living.

The book is available on major online platforms as well as in offline stores. To reserve your copy, click here: https://tinyurl.com/bdzd5fzb 

Disclaimer: The perspectives expressed in this book review reflect the reviewer’s own intellectual views and interpretations.