Some
emotion researchers suggest there are only a very small number of universal emotions:
fear, anger, happiness, sadness, surprise, and disgust (see October, 2013: http://prescotttastematters.blogspot.com.au/2013/10/feeling-all-emotional.html).
All other emotion terms, in this view, reflect these basic emotions. But even
if you are inclined to believe that there are dozens, if not hundreds, of
distinct emotional states, there remains one common indivisible emotion, disgust. Disgust sits alone in the cathedral
of emotions, shunned even by dislike, guilty
and worried. When talking about
emotions elicited by foods, the uniqueness of disgust is rather …. unique, in that it is the only emotion that
specifically implies a relationship to our sense of taste.
But,
of course, foods are not supposed to disgust us, and fortunately most of us
seldom come across examples of foods that do. Moreover, although our potential
experience and expression disgust is innate, we need to learn what things should
make us disgusted. It is a familiar enough scenario where a mother mimics the
classic disgust face to a child about to eat something they have picked up from
a footpath. With just a wrinkle of the nose, a baring of the upper teeth and a
gaping mouth (and perhaps a “Yuk!”), the mother teaches the child a lesson
about the potential dangers of otherwise edible items contaminated by …. who
knows what, but certainly something that might cause disease. This common sense
view is generally supported too by theoretical accounts of the evolutionary
purpose of such a strong emotion which stress its role as disease-prevention
mechanism [1].
Indeed,
we could argue that disgust – despite the origins of the word – has little to
do with taste or foods per se. Paul
Rozin has characterized disgust as the emotional aspect of fear of
contamination through, in the case of foods, consumption. Hence, food is just
one of those things that we stick in out mouths that could potentially cause us
harm via contamination. It is easy to show that food likes and dislikes show an
inconsistent relationship to disgust. So,
foods that are highly unpleasant, for example by being bitter, do not
necessarily, or even often, induce feelings of disgust. And, of course, it is possible for us to
recognize that foods from other cultures could potentially taste great and be
full of important nutrients, even if the idea
of them caused a distinct shuddering of the spine.
We can see an illustration of this in
the recent enthusiasm for insects as potential food sources in the future. A
small, but growing, movement is examining how best to take advantage of the nutrients
that insects can provide, and considering how best to deal with consumer
responses to this [2]. Because of this interest, which is strong
in Denmark, I was recently treated to a lunch provided by the Nordic Food Lab (www.nordicfoodlab.org), in which the
menu contained a dish labeled “Peas and
Bees”. The label was perfectly descriptive, and I managed to overcome my
urge to say “thank you, I’m already full”. Those expecting little yellow and
black highlights against the green background would have been disappointed,
however, as only bee larvae were used.
Disgust
doesn’t always require extreme foods or obvious contamination. Perfectly clean,
everyday foods in perfectly clean bedpans will do it, as will being offered a
glass of water into which a plastic model of a cockroach has been briefly
dipped. In an earlier posting, I noted the extreme reactions to a choc-mint
flavoured potato crisp (November, 2013: http://prescotttastematters.blogspot.com.au/2013/11/colour-me-minty.html).
In many respects, this response to violation of expectations is a co-opting of
so-called core disgust (that is,
associated with ingestion of a potential contaminant) to cover a situation in
which the unpredictability of the flavour could be a signal for possible
danger.
A
broadening of the disgust emotion to include those situations where
contamination in the physical sense is not a risk is also evident. We talk, for
example, about being disgusted by violence or by someone’s behavior or their
appearance or their table manners. At least some of these reactions can be
included under the term moral disgust.
Rozin [3] suggests that
the disgust emotion began life as an extension of our in-built responses to
bitterness to which we added a cognitive appraisal of other (whether bitter or
not) substances that we did not want to consume. This allows us to learn what
to be disgusted by as a function of culture or violated expectations.
Similarly, strong violations of beliefs, values or rules have become ‘attached’
to disgust. While we might just be using disgust as a metaphor in such
situations, there is evidence that it is something more fundamental. Thus, in
the same way that the classic disgust facial expression shares common features
with facial expressions to unpalatably bitter foods, it can be shown that both
core disgust and the moral disgust at being treated unfairly in a game activate
a very similar set of facial muscles [4]. So, at least the expression of
disgust appears to be highly similar.
A later study looked at associations between bitterness sensitivity, reflected in PROP taster status
(May, 2013: http://prescotttastematters.blogspot.com.au/2013_05_01_archive.html),
and different questionnaire scales of disgust sensitivity [5]. By
distinguishing between different types of disgust: visceral (related to
disease, bodily fluids and sexual activity) and moral, the study was able to
show that those most sensitive to the bitterness of PROP (supertasters) were also
significantly more sensitive to visceral disgust - that is, involving the
possibility of contamination through ingestion or otherwise - but not moral
disgust. It is possible therefore that the link between core disgust and moral
disgust is merely semantic or metaphorical. An alternative explanation,
however, is that (as suggested above) that across the two stages or jumps from
bitterness responses to core disgust to moral disgust, the link between taste
reactivity and moral disgust is weakened or lost.
In
either case, examining the origins of moral disgust provides further
opportunities to consider the possibility – raised in the previous two postings
– that the source of many of our more complex emotional or personality traits
can be found in quite fundamental early taste experiences.
1. Oaten, M.J., R.J. Stevenson, and
T.I. Case, Disgust as a Disease-Avoidance
Mechanism. PSYCHOL. BULL., 2009. 135(2):
p. 303-321.
2. Verbeke, W., Profiling consumers who are ready to adopt insects as a meat substitute
in a Western society. Food Qual Pref, 2015. 39: p. 147-155.
3. Rozin, P., From Oral to Moral. Science, 2009. 323: p. 1179-1180.
4. Chapman, H.A., et al., In Bad Taste: Evidence for the Oral Origins
of Moral Disgust. Science, 2009. 323:
p. 1222-1226.
5. Herz, R.S., PROP Taste Sensitivity is Related to Visceral but Not Moral Disgust.
Chem. Percept., 2011. 4: p. 72-79.
