Disgust: It's More Than You Think

There's a certain sense in which we all already know what disgust is. It's the feeling you have, the emotion you experience, when you read about something like this.

Actually, another bit of common knowledge about disgust that can get taken for granted is that it can vary a lot from culture to culture, or from person to person: sautéed mushrooms may be a delicacy to some people, but they're revolting to others. There's reason to think, though, that something like the ailment of cockroach-in-ear is disgusting to almost everyone, even people like doctors and medical students, whose daily routines land them in enough confronting situations that they've long since gotten over most of their squeamishness. So while the emotion of disgust exhibits some flexibility, and can be influenced by nurture-type factors, there are ways in which it has a fairly rigid nature as well. If you've had occasion to consider that before, it might have sparked a bit of curiosity: why is disgust like that? And how does it pull it off? And since we're here, it's also slightly curious that - at least if you're anything like me - you don't need to witness an actual case, or even see an nasty picture; merely reading a description of cockroach-in-ear is enough to totally gross you out.

I mention all this to head off a fair and relevant question: why a whole blog devoted to disgust and disgustingness? What more is there to say, other than "yuck!"? More than you might initially suspect, actually - certainly more than I suspected when the topic first caught my attention several years ago. In the coming months, I'll use this space to try to illustrate the many ways in which disgust can serve as a fascinating window into human nature, and our mental, social and, surprisingly, moral lives. Mixed in with this, I'll also be raising some of the more philosophical and ethical issues that the emotion has become intertwined with. For now, it might help to say a little about how someone in philosophy might come to dedicate a blog to, and write an entire book about, such a specific, not to mention unusual, topic. Some context will help.

Part of what led me to philosophy in the first place was a fascination with what makes people tick, what makes us humans special, and (of course) What It All Means. Once I got there, I was attracted to the exciting things happening at the intersection of philosophy and the cognitive sciences. My own research is based right at that crossroads; it tries to understand human activity and the human mind within a broadly naturalistic and scientific framework, and then to get a grip on the philosophical ramifications of that understanding. Put another way, I'm interested in the ways in which we are continuous with other animals, but also those respects in which we, and our cognitive, emotional and culture using repertoires, are unique - what is it is that marks us as distinct creatures in the natural world, and how should knowledge of the sort of critters we are inform how we choose to lead our lives?

Given this orientation, it isn't surprising, in retrospect, that I became intrigued by the recent wave of interdisciplinary research on moral psychology, on the one hand, and the new prominence of the emotions in cognitive science, on the other. Sitting enigmatically in the middle of a lot of this work was disgust. It's got that accompanying yuck-face that we all recognize, and occasionally make ourselves.

It's an emotion possibly possessed only by humans. It's biologically rooted but also extremely culturally variable. It seems obviously attuned to the muck and filth of the physical world but has also been shown to exert powerful, almost subliminal influence over certain kinds of social and moral judgments. Looking closer, I saw that different people theorizing about disgust where apt to make claims that were equally plausible, but that also looked incompatible with each other.

So there were plenty of puzzles beckoning. I suspected that making sense of everything we were learning about disgust would require weaving together ideas from several different approaches to explaining the operation and evolution of human minds. A richer understanding of the emotion itself, I hoped, would allow for a more informed examination of the more traditionally philosophic questions that the empirical research was raising, concerning whether the emotion should be invested with any kind of moral authority, or whether it is fit to be used as a social tool. Another thing I'll try and do in the coming months is flesh out these issues, and show why, when it comes to morality, we shouldn't trust disgust.

This is obviously a forest-rather-than-trees level preview, and so there are a lot of details to fill in and promissory notes that will need to be made good on. Stay tuned. And in the meantime, protect your ears.