Monday, March 09, 2009

From oral to moral

An interesting synthesis from Chapman et al.
In common parlance, moral transgressions "leave a bad taste in the mouth." This metaphor implies a link between moral disgust and more primitive forms of disgust related to toxicity and disease, yet convincing evidence for this relationship is still lacking. We tested directly the primitive oral origins of moral disgust by searching for similarity in the facial motor activity evoked by gustatory distaste (elicited by unpleasant tastes), basic disgust (elicited by photographs of contaminants), and moral disgust (elicited by unfair treatment in an economic game). We found that all three states evoked activation of the levator labii muscle region of the face, characteristic of an oralnasal rejection response. These results suggest that immorality elicits the same disgust as disease vectors and bad tastes.
A summary graphic from the review of this work by Rozin et al. and some of their comments:

Domains of disgust. The schematic represents routes by which eliciting situations may trigger the disgust output program. Those that run through the disgust evaluation system--which includes appraisal of the elicitor, feelings, and contamination ideation--trigger the full disgust emotion. Solid lines represent routes through which an elicitor can activate the disgust evaluation-output program. Dashed lines (green) represent direct elicitation of the disgust output program. The dotted line (brown) represents a metaphoric, indirect route.

According to the principle of preadaptation, a system that evolves for one purpose is later used for another purpose. From this viewpoint, disgust originates in the mammalian bitter taste rejection system, which directly activates a disgust output system. This primal route (e.g., bitter and some other tastes) evokes only the output program, without a disgust evaluation phase. During human evolution, the disgust output system was harnessed to a disgust evaluation system that responded not to simple sensory inputs (such as bitter tastes) but to more cognitively elaborated appraisals (e.g., a cockroach). Initially, the evaluation system was a food rejection system that rejected potential foods on the basis of their nature or perceived origin. This was the first "true disgust," because it engaged this evaluation system. Later, through some combination of biological and cultural evolution, the eliciting category was enlarged to include reminders of our animal nature, as wel as some people or social groups. This process had adaptive value, because by making things or thoughts disgusting a culture could communicate their negativity and cause withdrawal from them.

1 comment:

  1. I think we have to push the ideas of evolution to gain insight into the humanness of human being. I listened to a participant from this years T.E.D. gathering interviewed on NPR recently. He was all excited at the prospect that human being would soon be able to influence evolution by gene therapies etc. Yet, when I read studies such as this one above, I see exemplified, our abilities to create and connect from an expanded subjectivity; we adapt something known to communicate something transcending the known: the distaste born of neural reflex is made to communicate something born of something considered. Somehow, this TED participant seems blind to the evolution of which we are the authors.

    Toward the development of another branch of evolution if you will, I would table Masilov's pyramid shaped, 'hierarchy of needs' for a simple ellipse: the shape derived by two poles; one pole denoting that of physical processes the second pole denoting processes that we call 'spiritual'. Take away either pole and human being disappears

    I'm not using spiritual with any religious or theistic connotations here; I am using it to denote things like the aspects of love that transcend underlying physical processes and affect first hand, our vitality as living beings.

    It seems to me that when I employ a biologically reflexive experience to communicate more fully and meaningfully, I am transcending reflex and am engaging creatively in a domain beyond utility. This other domain, the second pole of our polar unity seems to transcend utility and the schemes of evolution that embody utility.

    By employing the concepts of ellipse, domain, creative and spiritual, I'm trying to communicate the actual 'solidness' of the intangible parts of ourselves, that are equally vital to us as the tangible. It is in this part of us that I'm here, calling spiritual, where we can- and need- to affect our other kind of evolution: because if we don't, life may have to resort to another species to evolve a human level of consciousness to take our place.

    If we began considering evolution as consisting differently in two domains, the one being uniquely human and that we can affect, then what would our second theory consist of?

    And so I don't sound totally off the subject, while I was writing this comment, I noticed my brow
    shaping my eyes to the form used for peering into a darkened room.