In 1901, David Hänig published a paper
that forever changed 
our understanding of taste.
His research led to what we know 
today as the taste map:
an illustration that divides the tongue 
into four separate areas.
According to this map,
receptors at the tip of our tongues
capture sweetness,
bitterness 
is detected at the tongue’s base,
and along the sides, receptors capture 
salty and sour sensations.
Since its invention, the taste map 
has been published
in textbooks and newspapers.
The only problem with this map, 
is that it’s wrong.
In fact, it’s not even 
an accurate representation
of what Hänig originally discovered.
The tongue map is a common misconception—
something widely believed 
but largely incorrect.
So where do misconceptions 
like this come from,
and what makes a fake fact 
so easy to believe?
It’s true that the tongue map’s 
journey begins with David Hänig.
As part of his dissertation 
at Leipzig University,
Hänig analyzed taste sensitivities across 
the tongue for the four basic flavors.
Using sucrose for sweet, 
quinine sulfate for bitter,
hydrochloric acid for sour, 
and salt for salty,
Hänig applied these stimuli to compare 
differences in taste thresholds
across a subject’s tongue.
He hoped to better understand 
the physiological mechanisms
that affected these four flavors,
and his data suggested that sensitivity 
for each taste
did in fact vary across the tongue.
The maximum sensation for sweet 
was located at the tongue’s tip;
bitter flavors were strongest at the back;
salt was strongest in this area,
and sour at the middle 
of the tongue’s sides.
But Hänig was careful 
to note that every sensation
could also be tasted across the tongue,
and that the areas he identified offered 
very small variations in intensity.
Like so many misconceptions,
the tongue map represents a distortion 
of its original source,
however the nature of that distortion 
can vary.
Some misconceptions 
are comprised of disinformation—
false information intentionally designed 
to mislead people.
But many misconceptions, 
including the tongue map,
center on misinformation—
false or misleading information
that results from unintentional 
inaccuracy.
Misinformation is most often shaped 
by mistakes and human error,
but the specific mistakes 
that lead to a misconception
can be surprisingly varied.
In the case of the tongue map,
Hänig’s dissertation was written 
in German,
meaning the paper could only be 
understood by readers fluent in German
and well versed in Hanig’s 
small corner of academia.
This kicked off a game of telephone 
that re-shaped Häing’s research
every time it was shared 
with outside parties.
Less than a decade after his dissertation,
newspapers were falsely insisting 
that experiments
could prove sweetness was imperceptible 
on the back of the tongue.
The second culprit 
behind the tongue map’s spread
were the images 
that Hänig’s work inspired.
In 1912, a rough version of the map 
appeared in a newspaper article
that cautiously described 
some of the mysteries
behind taste and smell research.
Featuring clear labels across the tongue,
the article’s illustration
simplified Hänig’s more-complicated 
original diagrams.
Variations of this approachable image 
became repeatedly cited,
often without credit or nuanced 
consideration for Hänig’s work.
Eventually this image spread 
to textbooks and classrooms
as a purported truth 
of how we experience taste.
But perhaps the factor that most 
contributed to this misconception
was its narrative simplicity.
In many ways,
the map complements our desire for clear 
stories about the world around us—
a quality not always present 
in the sometimes-messy fields of science.
For example,
even the number of tastes we have is more 
complicated than Hänig’s work suggests.
Umami— also known as savory— 
is now considered the fifth basic taste,
and many still debate 
the existence of tastes
like fatty, alkaline, metallic, 
and water-like.
Once we hear a good story,
it can be difficult to change 
how we see that information,
even in the face of new evidence.
So, next time you see a convenient chart 
or read a surprising anecdote,
try to maintain a healthy skepticism—
because misconceptions 
can leave a bitter taste
on every part of your tongue.
