When deciding difficult questions, we often rely on intuitions in the form of ‘gut instinct’. The emotions involved in moral decision-making can be connected to a visceral sensation that clenches the torso or tingles the appendages. Our bodies are involved in our moral choices.
Martha Nussbaum, Leon Kass, Jonathan Haidt and others have written about the authority we should give this type of feeling about transgressions: whether you call it abhorrence, revulsion, repugnance or horror, we give these feelings great power over ourselves and our societies. They buttress taboos, and influence law and policy.
This became a live issue in bioethics, where the phrase ‘yuk factor’ was used to describe how some issues are capable of stirring public emotions against cloning and related biotechnologies. For a while the idea was involved in a lot of public debate, ranking up there with the ubiquitous ‘playing god’ objection – a precautionary principle intended to restrain the hubris of mad scientists.
If so, bioethicists can revisit research into the biological origins of disgust by looking at the work by Daniel Fessler. When he isn’t looking at how different cultures use foot size to evaluate physical attractiveness (among other fascinating anthropological topics), he is inquiring into the evolutionary origins of disgust. His papers are available for download via his website, and I hope to write in a future post about his research into the disgust moral vegetarians feel toward meat eating.
In his present work, he is evaluating the evolutionary advantage of disgust. Since disgust is connected with behavioural taboos and injunctions, it makes sense to wonder if there is an evolutionary advantage to moral feelings of revulsion, and how this changes brain structures over time.
This led me to ponder if other animal species experience neurological phenomena similar to the type we associate with disgust and moral feelings. So I now have two questions for people in the know:
- What neurological mechanisms might make us capable of thinking away feelings of moral revulsion?
- Do other species exhibit the neurological phenomena we see in human moral judgements? What species even have the requisite brain structures?
I’m not enough of an experimentalist to even begin to wonder how that last topic might be answered, so I would value any comments directing me to papers in this area. It would be nice to know what makes Flipper go ‘eww’ instead of ‘eee’.
The behavioural psychology related to this is widely available in publications for a popular audience. Just in the last year months we have:
- Frans der Waal’s Primates and Philosophers (other publications)
- Marc Hauser’s Moral Minds (other publications)
- Richard Joyce’s Evolution of Morality
The growing body of literature would be complemented by cross-species neuroimaging studies, but on a trivial level I’m having difficulty getting the image of elephants racing along a track out of my head. Who knows how pachyderms would respond to the trolley problem? I suspect they’d sympathize with the fat guy.