No, you don't have to eat your broccoli.
In an experiment that sounds like something we should
have done like 70 years ago, we discover that all
noses are not created equal. We all smell things differently, perceiving
particular odor-features with varying levels of intensity.
I take it back; we didn't have the ability to do this
kind of genetics testing 70 years ago. This new experiment showed that of the
~400 genes that control our ~400 different olfactory receptors, the variability
is on high. In other words, let's say broccoli has a bunch of different
chemicals that make it smell like "broccoli," and that there's a
bunch of different receptor-genes that code for those chemicals -- you and I
have slightly different versions of those receptors, which make one of us more
sensitive to the bad parts of the smell, and maybe even the other of us more
sensitive to the good parts.
What you get is one person who doesn't mind eating
broccoli, and one of us who gets less ice cream after dinner everytime broccoli's on
the menu.
What you also get is an entire sense which lacks in
consensus. At the genetic level, what smells good to you won't necessarily
smell good to me. So how do we agree?
As groundbreaking a breakthrough as this is, it doesn't
even begin to scratch the surface as to how different each of our olfactory
experiences are. Each one of us really does live an olfactory world all to
ourselves.
We know then that genetics separates us, but it goes even
further. Genetics is the hardwiring, but what about the softwiring? If you, for
example, were force-fed broccoli while at the same time you're also forced to
watch, with your eyes pried open, footage of people trying to peel the foil off
a Nutella jar but it rips halfway
through, then you might become traumatized by the smell of hot broccoli, and
hence highly sensitive, and highly averse to it.
And the reverse can also happen. Don't like Flowerbomb?
Wait until you have a few too many romantic encounters with a woman who wears
it, and you'll change, you'll see. That's
softwiring. Humans are special because of our neural plasticity, so you can bet
we're susceptible to these kinds of changes.
The final note here needs to be on the way we talk about
smells. If we all smell a bit different, then how can we really communicate our
experiences to each other with any fidelity?
Notes:
C. Trimmer, A.
Keller, N. R. Murphy, L. L. Snyder, J. R. Willer, M. H. Nagai, N. Katsanis, L.
B. Vosshall, H. Matsunami, and J. D. Mainland
PNAS May 7, 2019
116 (19) 9475-9480; first published April 30, 2019
Heather Murphy for
the New York Times, May 2019
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