Dr Valerie Curtis from the London School of
Hygiene and Tropical Medicine, surveyed people
from different countries to find out what they found
disgusting.
Cultural peculiarities included:
Food cooked my menstruating women was
a frequent cause of disgust in India.
Fat people scored highly as
disgusting in the Netherlands.
Overall people kept reporting
the same things as disgusting,
wherever they were from:
Decaying food - especially
rotting meat and fish, rubbish.
Certain living creatures - flies,
maggots, lice, worms, rats,
dogs and cats.
People who are ill,
contaminated.
This led Curtis to hypothesis that disgust might
be genetic; hard-wired in our brains and
imprinted on our biological code by millions of
years of natural selection.
The origin of faeces.
Excreta is the most common
cause of disgust around the world.
This convinced Curtis that disgust
was a biological mechanism for
avoiding infectious disease.
The genes for disgust probably arose
by accident and then became common
through natural selection.
The observation that most animals
avoid eating each other's faeces
suggests that disgust could have
evolved a very long time ago.
Unwashed genes.
Curtis still believes that upbringing plays an
important role in determining what we find
disgusting. But she believes that we have evolved
genes that predispose us to find some things more
disgusting that others.
Opposing views.
Paul Rozin of Penn State
University believes that disgust
is culturally acquired.
He carried out his own study on
things people found disgusting and
discovered the causes of death
rated highest amoungst his North
American subjects.
"Anything that reminds us we are animals
elicits disgust." "Disgust functions like a
defence mechanism, to keep human
animalness out of awareness."
Anatomy of disgust.
Professor Paul Ekman of the University of
California found that our facial expression
for disgust was identical in different cultures
around the globe.
We make this expression by
screwing up our noses and pulling
down the corners of our mouths.
MRI scans also reveal that we use a
special part of the brain when we get
disgusted: the anterior insular cortex.
Curtis has even claimed that
disgust could have been one of the
first words uttered by humans.
The word "Yuck" is similar in
languages all over the world.