The Instigator
Pro (for)
3 Points
The Contender
Con (against)
1 Points

The IQ of a banana is more than 0

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Post Voting Period
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after 1 vote the winner is...
Voting Style: Open Point System: 7 Point
Started: 1/6/2014 Category: Science
Updated: 2 years ago Status: Post Voting Period
Viewed: 3,872 times Debate No: 43502
Debate Rounds (3)
Comments (2)
Votes (1)




I will argue that the Intelligence Quotient of a banana is more than 0.
For an explanation of IQ, see;

CON can start the debate. I wish my opponent, whoever it may be, good luck.


My primary argument will consist of this claim.

It lies in how IQ is calculated. The formula for IQ is {IQ=(mental age/calendar age)x100}. The definition of 'mental', according to Merriam-Webster Online Dictionary, is, "of or relating to the mind," and the definiton of 'mind' is, from the same source, "the conscious mental events and capabilities in an organism. " Now, since "consciousness arises as an emergent property of the... brain", it can be concluded that bananas do not have consciousness as they do not have brains (as seen in the image below), and thus do not have a mental age.
Debate Sources
Since a mental age is nonexistent, 0 can be substituted into the formula. Using the Zero Product Property of Multiplication, it can be deduced that the final IQ of a banana is equal to 0.
Debate Round No. 1


How to calculate IQ

The formula that my opponent gave for computing IQ was used in the early 20th century. In modern time, the IQ is assumed to be distributed as a normal random variable with mean 100 and standard deviation 15. The definition in the link I provided in the first round has the modern definition of IQ. It should have been clear that I was not referring to the old "mental age" formula.

If Phi(x) is the cumulative distribution with mean 0 and standard deviation 1, then the fraction of the population with an IQ less or equal than y is z=Phi( (y-100)/15 ). For example, the fraction of people with an IQ <= 70 is Phi((70-100)/15)=Phi(-2)=0.02275.
So about 2.275 % of the population has an IQ <=70. We can safely say that the IQ of a banana is probably less than 70.

How smart is a banana compared to humans? On standardized tests, bananas score the same as people in a persistent vegetative state.

"In the United States, it is estimated that there may be between 15,000–40,000 patients who are in a persistent vegetative state, but due to poor nursing home records exact figures are hard to determine."

As of January 6, 2014, the United States has a total resident population of 317,413,000.The fraction of the population with an IQ less or equal than a banana is roughly 15,000/300,000,000=1/20,000.
We now solve

If y is the IQ of a banana, we get the equation Phi((y-100)/15)=0.00005.
(y-100)/15=-3.89. Solving this yields y=15*(-3.89)+100=41.65.

So the IQ of a banana is about 42, significantly higher than 0.

Do banana's have brains?

The computation of the IQ of a banana by my opponent using the wrong definition also relies on the assertion that bananas do not have brains. An image of the outside of a banana does not constitute a proof. For example, a walnut may not look very intelligent on the outside but if you crack open its skull you see that it does have a brain.



How to calculate IQ

I apologize for my misunderstanding. I actually retrieved the 'mental age' formula from a link from the original source, and used it. The source quoted by my opponent was quite vague on the subject of IQ and relied on several sources with various explanations. (If the Pro can cite exactly which link his definition was found, it would be appreciated.)

However, I will still concede to my opponent and rely upon the modern IQ model.

Now, my opponent made a number of deductive errors here. First, he failed to identify how IQ is measured from people in a persistent vegetative state. It should be noted that "Most PVS patients are unresponsive to external stimuli and their conditions are associated with different levels of consciousness."

Of course, 'most' is not absolute, but it can be safely assumed that bananas are likewise "unresponsive to external stimuli." This would make it impossible to determine the IQ of a banana (or a person in a PVS) without an examination of its brain in action. In other words, an MRI scan on a banana's brain would have to be taken in order for its IQ to be determined. I will return to this conclusion shortly.

"The fraction of the population with an IQ less or equal than a banana is roughly 15,000/300,000,000=1/20,000."

Here my opponent falsely assumes that bananas are at the upper end of this region, when they may very well be the bottom-most occupant and have an IQ of 0.

Additionally, on source linked from the original states that an IQ of 1-24 correlates with "profound mental disability."

Suggesting a banana is more intelligent than any human, even with profound mental disability, is absurd, but I will continue.

Do bananas have brains?

Even without using the 'mental age' calculation, it can be concluded that a brain is necessary for a determination of IQ. I concluded that a scan is needed to find a banana's IQ, and without a brain, a scan would be fruitless and yield NO results of electrical signals being transmitted through a central processing unit commonly known as a brain. Thus, their IQ would be 0.

Now, my opponent used an image of an open walnut to conclude that bananas may have brains. However, he failed to realize he made three crucial errors in this conclusion.

The first is that walnuts are not bananas. Walnuts are members of the Juglandaceae family, while bananas are members of the Musaceae family. They are not closely enough related to be comparable.

His second error lies in his assumption that having a brain correlates to intelligence, "a walnut may not look very intelligent on the outside but if you crack open its skull you see that it does have a brain." This argument surprised me in its astuteness. My opponent's previous arguments had been thinly veiled, but not this one. The reason I have taken all this time to come up with a rebuttal lay in this conundrum.
Finally, I figured it out. Dead people have brains as well, but have no cognitive abilities. Likewise, walnuts may appear to be intelligent, but have no thinking abilities. If there is evidence otherwise, I would gladly listen.

The final error in judgment was that the Pro overlooked the main part of my picture. "An image of the outside of a banana does not constitute a proof." This is true, but my picture actually shows a banana cut in half juxtaposed with a full banana. It may appear like two attached fruits, but it is in fact not. The inside reveals that no brain was present.

Debate Sources

The only way this can be refuted is if my opponent presents some definite proof of the existence of a brain in a banana.


Another issue arising in my opponents argument using the standard deviation model of IQ is a problem in distribution.

If all bananas are accounted for, serious issues emerge. There were 107142187 TONNES of bananas harvested globally in 2011.

Considering that the average weight of a banana is 125 grams (.125 kg), and a tonne is equal to 1000 kg, it is calculated that 857137496000 bananas existed that year alone. Adding this population to the human population and assuming that its IQ is a measurable statistic above 0 would tilt the scale and completely void the distribution model.

Pro must reconcile this with his equations to justify a banana having an IQ of greater that 0, let alone an IQ at all.
Debate Round No. 2


The link that I meant to refer to in the first round was
For some reason, additional characters were added at the end of the web address, making
it point to a different web page. My apologies. I should have checked whether the link works.

Anyway, we agree that the modern way of calculation the IQ (using mean 100 and standard deviation 15)
is the best way. The "mental age" definition does not make much sense. For example, a dumb 40-year old
who has the intelligence of a senile 120 year old, would have an IQ of 120/40*100=300.

Brain of a banana

For the "mental age" definition, the IQ of a banana may not make sense if we can establish that a banana
does not have a brain. However, I think a brain is not needed for the modern definition of the IQ. To measure
an IQ, one has to participate in a standardized test. However, it is possible to perform worse than a banana.

For example at an SAT test, you're score for a question is 0 if you don't answer it. It is 1 if you answer it incorrectly
and you get a negative score for wrong answers. Most of the time, bananas score 0 on such a test, but some people score
below that. Scoring 0 on an SAT test or an intelligence test does not mean that your IQ is 0 though. Remember that
the IQ is defined in terms of how you score relatively to the adult human population.

Still, I do not agree that bananas do not have brains. The resolution of your image was too low for me to recognize
that there were only 2 bananas, of which one was cut open. To me it just seemed to be 3 bananas. The resolution is also
too low to recognize, whether the inside of the banana is a brain or not. It doesn't quite look like the inside of a walnut
or like the human brain. But for example, if you compare the inside of a banana with the brain of a mouse, a rat or
even a rabbit, then it does not look that different as the following image shows:

The human brain (and the walnut's brain) have lots of folds, whereas the brain of a rat looks more like a piece of fruit.

My opponent wrote:" I concluded that a scan is needed to find a banana's IQ, and without a brain, a scan would be fruitless and yield NO results of electrical signals being transmitted through a central processing unit commonly known as a brain. "

My opponent argues, that, if a banana has no brain, then a brain scan of a banana would be fruitless.
It is well known that banana's are fruits. So any brain scan of a banana is fruitful, not fruitless. The logical conclusion is
that bananas do have brains.

It should also be pointed out that not all humans are smarter than bananas. Banana's don't talk. But sometimes
being silent makes you smarter. Look at the video.

then look at this banana:

Now, which one looks more intelligent to you?

I think for some people, going bananas is a step up.

Calculation of IQ

Bananas and people in permanent vegetative states have similar scores on IQ tests. I should not have assumed that bananas
are in the upper end of this spectrum as my opponent points out. More reasonable would be to assume that
there score average among this group. In that case, the fraction of the population with an IQ less or equal than a banana
is roughly 1/40,000.

Doing the same calculation as before we get
So the IQ of a banana is about 39.

This likely will not satisfy my opponent. So let us for the moment assume that a banana scores as badly as the stupidest person on earth. Let's say there are 7,136,000,000 people.
Phi((y-100)/15)=1/7,136,000,000 (It's kind of hard to solve this with a regular calculator, I used MATLAB)
So even under this assumption, the IQ of a banana is more than 5!

Finally, we talking about human IQ. We are just looking what the human-IQ of a banana is. Adding the whole banana
population to the human population would change the definition of an IQ. Since there are many more bananas than people,
basically we would get the "banana-IQ". So a banana has a banana-IQ of 100, but humans have a banana IQ of 200 or maybe 300.
(I don't have the energy to compute it now though.)



First I would like to apologize for the delay. I didn't see the notification for the debate, and am now left with only thirty minutes to reply. However, that should not be perceived as an

Brain of a banana

Contrary to what my opponent pointed out, a brain is necessary for bananas to have an IQ. Several issues arise if it does not.

For instance, if IQ measures cognitive ability or intelligence, the logical conclusion would be that a brain is required for any thought processes to occur. IQ stems from cognicence, and cognicence stems from the brain.

Also, my opponent points out that a search for a banana's brain would indeed be fruitful. I overlooked this aspect, but still uphold that this means only that much 'fruit' will be found. Fruit =\= Brain

My opponent failed to provide any evidence for the existence of a brain, and instead relied on semantics to support his claim. Here is another image with higher resolution, of the inside of a banana. Note that there is, again, no brain in sight.

Calculation of IQ

Addtionally, my opponent provided arguments as to why bananas would still score a 5 on a modern IQ test. As a rebuttal, I offer the following scenario.

The mean IQ is 100, as previously established. However, there have been people with an IQ of over 200, which is 100 more than 100. If IQ's are evenly distributed as thought to be, it can be concluded that an equal number of people/vegetables/fruits must exist on each variation from 100 (e.g. if there are 10 with an IQ of 195, there must be 10 with an IQ of 5).

In conclusion, I believe I have provided enough evidence to disprove the notion that a banana has an IQ greater than 0 by showing that it is a statistical possibility and that brains, which bananas don't have, are needed to have an IQ at all. (Plus I'm out of time).
Debate Round No. 3
2 comments have been posted on this debate. Showing 1 through 2 records.
Posted by Ralphacus 2 years ago
This has got to be the funniest debates I have ever seen! I cant vote because of the regulations but I think that black_squirrel won this debate just because of that amazing maths and logic that somehow made sense.
Posted by dmussi12 2 years ago
My first paragraph of the third round should end with the word "excuse."
1 votes has been placed for this debate.
Vote Placed by Buckethead31594 2 years ago
Agreed with before the debate:--Vote Checkmark0 points
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Had better spelling and grammar:--Vote Checkmark1 point
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Total points awarded:31 
Reasons for voting decision: At a glance, I thought this was a joke- but after reading through the debate, I am thoroughly impressed with both debaters. The only issue I found was where Con conceded Pro's best argument in Round Two; because of this, I thought Pro's arguments were stronger. Nonetheless, I will give conduct points to Con for their clever responses. What a fun debate!