a theory on intelligence

[grimbold]

I've been kickin around a theory lately about intelligence and wanted to know what the playground thought.

Basically 1 intelligence=10 iq points

This actually makes a lot of sense because 10-11 INT is about 100-110 IQ points which is about average.

120-139 IQ points is considered 'Gifted' which is equivalent to 12-13 INT which is above average or +1
140-159 IQ points is considered "Genius" Which corresponds with 14-15 INT and +2
160-179 IQ points (Think Leonard from big bang theory) is considered "Super Genius" which corresponds with 16-17 intelligence
180+ IQ points is basically off the charts and the highest possible for any human which makes sense as it is the highest possible roll to get. 18 INT

thoughts?

[WinWin]

Intelligence quotient is based on the statistical mean. Once you start moving more than 2 or 3 deviations away from the mean, intelligence becomes more and more difficult to measure accurately via a standardised test. People with a predicted IQ >130 may need extensive testing to find their actual score. A score over 150 is extremely difficult to measure and represents the range of most standardised tests.

Obviously there are methods of testing very high IQ, otherwise people would not know that Marylin Monroe had an IQ greater than Albert Einstien (came up in a pub quiz, could very well be false).

It may be a good ad hoc ruling though, but not perfectly accurate.

[Serpentine]

Uh... I'm pretty sure this has been very well established as a (very, very rough) approximation. Like, semi-officially, somewhere?

[Yuki Akuma]

This has been established for a while. It's also patently ridiculous - IQ does not work that way.

Someone with an IQ of 150 is not "twice as smart" as someone with an IQ of 75.

[grimbold]

yuki i did not say that nor do the D&D rules state that. They just state that someone with 15 INT (or 155 IQ) is significantly smarter than someone with 7 INT (Or 75 IQ points)
i did not realize this was already established

[Yora]

It works as a reasonable well approximation. And given that Intelligence represents pretty much the same thing IQ-test measure, it makes sense to apply the same scale.

[Foryn Gilnith]

180+ IQ points is basically off the charts and the highest possible for any human

I'd contest that; even disregarding age (because unlike D&D people, real-life IQ doesn't rise significantly with age. IIRC it decreases, although that's probably just because of perception defects affecting the test-taking). It only takes 3 levels to finish Human Paragon and get a +2 to Intelligence; an additional level can get a +1. Now, IQ does in extreme WTF cases go up to about 200 before being unmeasurable, so one can account for that.

[hamishspence]

I've seen a lot of arguments saying it doesn't work- however they seem to be based on the assumption that everyone who is not an adventurer rolls 3d6 for Int.

Suggesting that 1/216 of the common population are Int 3- and so would be IQ 30.
And that 1/216 of the common population are Int 18- and so, IQ 180.

Which is nothing like the real statistics.

However- that may be an unwarranted assumption. It's possible that the majority just use a Non-Elite (runs 13 to 8), or an Standard Array (that has 3 10s and 3 11s).

And that the vast majority of NPCs with adventurer classes, use the Elite Array (15 to 8)

As a result, characters with 3s or 18s for Int, would be far rarer than if everybody rolled 3d6 for it.

Thus, the "statistics don't support the Int = IQ/10" argument may not work.

I'd contest that; even disregarding age (because unlike D&D people, real-life IQ doesn't rise significantly with age. IIRC it decreases, although that's probably just because of perception defects affecting the test-taking). It only takes 3 levels to finish Human Paragon and get a +2 to Intelligence; an additional level can get a +1.

There's also the Special Abilities list of templates in DMG2- one is Prodigy- Extraordinary and allows an NPC to start out with +2 to a stat, and a +5 bonus to ability checks with that ability.

So this may account for those really exceptional at 1st level.

140-159 IQ points is considered "Genius" Which corresponds with 14-15 INT and +2
160-179 IQ points (Think Leonard from big bang theory) is considered "Super Genius" which corresponds with 16-17 intelligence

In 2nd ed "Genius" was used for Int 18, and "Supra-genius" for Int 19.

[Yora]

Also, we're talking about D&D, a franchise that never bothered much with realism.

[Prime32]

This has been established for a while. It's also patently ridiculous - IQ does not work that way.

Someone with an IQ of 150 is not "twice as smart" as someone with an IQ of 75.

Someone with an Int of 15 is twice as smart as someone with an Int of 10.

[grimbold]

Someone with an Int of 15 is twice as smart as someone with an Int of 10.

not neccessarily there is no proof of this

[hamishspence]

Someone with an Int of 15 is twice as smart as someone with an Int of 10.

What deduction got this?

Do people with Int 15 solve problems twice as fast by strict reading of the rules?

Or is it based on the probability of passing opposed Int Checks being twice as high?

[Lev]

Someone tried to do this a while ago, it failed terribly.

[Synapse]

Also, we're talking about D&D, a franchise that never bothered much with realism.

This coupled with the limited actual uses of IQ leads me to this question: What do you gain by making such a comparison?

[Kurald Galain]

Here's another reason why it doesn't work: the difference between a +0 and a +1 on skill checks is way too small to account for the difference between 100 IQ and 120 IQ.

For instance, consider a high school math test that is DC 11. It works with any other kind of skill check or knowledge check as well, this is just an example. Now take an average group of high schoolers of average intelligence, which in this case means 100 - 110 IQ. This is a difficult test, in that only half of the high schoolers will pass it.

Now consider another group of highly intelligent people that have IQ 120 - 130. According to D&D rules, 55% of them will pass this test. If you try this in reality, it is much more likely to find that 90-95% of them pass the test. Even funnier, if you take a group of the smartest people ever (IQ 180+, and yes, I know that IQ tests cannot actually measure that), then by D&D rules only 70% of them will pass the high school math test. Wow, math sure is hard!

[WinWin]

I'd contest that; even disregarding age (because unlike D&D people, real-life IQ doesn't rise significantly with age. IIRC it decreases, although that's probably just because of perception defects affecting the test-taking). It only takes 3 levels to finish Human Paragon and get a +2 to Intelligence; an additional level can get a +1. Now, IQ does in extreme WTF cases go up to about 200 before being unmeasurable, so one can account for that.

Actually...I saw a documentary on the history of IQ tests in Britain. They took a group of Scottish students that were among the first to ever take the tests and then compared their results to tests taken 40 years later.

Those with an IQ >120 all showed an increased in IQ. Those of avarage and below average scores did not show any great improvement or decline.

Not enough data to form any conclusions, but it certainly merits further investigation.

[grimbold]

Here's another reason why it doesn't work: the difference between a +0 and a +1 on skill checks is way too small to account for the difference between 100 IQ and 120 IQ.

For instance, consider a high school math test that is DC 11. It works with any other kind of skill check or knowledge check as well, this is just an example. Now take an average group of high schoolers of average intelligence, which in this case means 100 - 110 IQ. This is a difficult test, in that only half of the high schoolers will pass it.

Now consider another group of highly intelligent people that have IQ 120 - 130. According to D&D rules, 55% of them will pass this test. If you try this in reality, it is much more likely to find that 90-95% of them pass the test. Even funnier, if you take a group of the smartest people ever (IQ 180+, and yes, I know that IQ tests cannot actually measure that), then by D&D rules only 70% of them will pass the high school math test. Wow, math sure is hard

this is the reason why i try not to think to hard about D&D logical fallacies :(

[Foryn Gilnith]

this is the reason why i try not to think to hard about D&D logical fallacies :(

It's also why the Player's Handbook says

In some cases, an action is a straight test of one’s ability with no luck involved. Just as you wouldn’t make a height check to see who is taller, you don’t make a Strength check to see who is stronger. When two characters arm wrestle, for example, the stronger character simply wins.

It's not a perfect patch (it arguably doesn't even apply to the obvious example of a math/IQ test), but I think that the designers were vaguely considering it in some corner of their heads.

[Ormur]

If Int equaled IQ I'd think it made much more sense presuming people rolled a 3d6 (the average array could just be an abstraction for non-important characters and monsters) which would give you much lover IQ's. It's much more likely for someone to roll an 18 on Int than to have an IQ of 180. Int 18 is closer to IQ 140+.

Of course this all breaks down whatever method you use because Int can go higher than 18, races have bonuses, age categories add to it as well as stat increases (although they hardly kick in until the superhuman levels). IQ however is based on standard deviation so it's a statistical measurement.

They also represent some mechanical bonuses and attributes that aren't necessarily linked to IQ as they are described. D&D really isn't a good simulation of realty.

[Crow]

Intelligence in D&D is more a person's ability to learn and retain information.

Problem solving ability and logic are better represented in D&D by wisdom.

[Godskook]

Also, we're talking about D&D, a franchise that never bothered much with realism.

Huh? Are you talking about 3.5?

[Urpriest]

Intelligence in D&D is more a person's ability to learn and retain information.

Problem solving ability and logic are better represented in D&D by wisdom.

I'd contest that. Every D&D logic puzzle or problem solving activity in every published module I've ever seen was an Int check if it was a check at all. I've never seen one based on a Wis check.

[World Eater]

Here's another reason why it doesn't work: the difference between a +0 and a +1 on skill checks is way too small to account for the difference between 100 IQ and 120 IQ.

For instance, consider a high school math test that is DC 11. It works with any other kind of skill check or knowledge check as well, this is just an example. Now take an average group of high schoolers of average intelligence, which in this case means 100 - 110 IQ. This is a difficult test, in that only half of the high schoolers will pass it.

Now consider another group of highly intelligent people that have IQ 120 - 130. According to D&D rules, 55% of them will pass this test. If you try this in reality, it is much more likely to find that 90-95% of them pass the test. Even funnier, if you take a group of the smartest people ever (IQ 180+, and yes, I know that IQ tests cannot actually measure that), then by D&D rules only 70% of them will pass the high school math test. Wow, math sure is hard!

INT 10 people usually just roll the die.
Higher INT people remember to pile on modifiers and take 10.

[Kurald Galain]

INT 10 people usually just roll the die.
Higher INT people remember to pile on modifiers and take 10.

That's funny, but it still doesn't work.

Let's look at an opposite example: a first-year university test in quantum physics. Suppose the university students have int 14, two ranks in the relevant knowledge skill, and +2 circumstance bonus for masterwork textbooks. As you say, these people pile on modifiers and take 10, and therefore have no problem taking a DC 16 exam.

There are two problems here. First, every student passes the test, which is unlikely. Second, if you give this test to a bunch of average high schoolers who've never heard of quantum physics before, then 20% of them will pass the test anyway.

[shadow_archmagi]

Only adventurers roll for stats

As such, if you meet anyone that's significantly dumber than average, you should be nice to them, as they're probably a PC. murderous millionaire hobo.

[Urpriest]

That's funny, but it still doesn't work.

Let's look at an opposite example: a first-year university test in quantum physics. Suppose the university students have int 14, two ranks in the relevant knowledge skill, and +2 circumstance bonus for masterwork textbooks. As you say, these people pile on modifiers and take 10, and therefore have no problem taking a DC 16 exam.

There are two problems here. First, every student passes the test, which is unlikely. Second, if you give this test to a bunch of average high schoolers who've never heard of quantum physics before, then 20% of them will pass the test anyway.

Knowledge is trained-only.

Otherwise valid point.

[Prime32]

Huh? Are you talking about 3.5?

You, uh, have to put in a URL first.

[jebob]

WARNING: maths buffs only

Spoiler

Show

INT 18 happens 1 in 216 times, so about 0.5% of the time. Three standard deviations is 99.9% (good enough). The SD for IQ is defined to be 15, so an INT 18 character will have about 145 IQ. INT 3 is 55 IQ.

Wow, A-level maths turned out to be useful

[crimson77]

I wrote a blog post recently on this very topic.

[hamishspence]

INT 18 happens 1 in 216 times, so about 0.5% of the time. Three standard deviations is 99.9% (good enough). The SD for IQ is defined to be 15, so an INT 18 character will have about 145 IQ. INT 3 is 55 IQ.

I already brought this up in a previous post, and went on to say:

However- that may be an unwarranted assumption. It's possible that the majority just use a Non-Elite (runs 13 to 8), or an Standard Array (that has 3 10s and 3 11s).

And that the vast majority of NPCs with adventurer classes, use the Elite Array (15 to 8)

As a result, characters with 3s or 18s for Int, would be far rarer than if everybody rolled 3d6 for it.