Should you administer IQ tests to programmers during the interview process?

Question

How many companies are using IQ tests to rate prospective programmers?

How would you weight an IQ test vs. education, experience, etc.?

Are there any legal issues that come into play with this kind of thing?

Is there an industry standard test?

[Edit]

WOW, I wasn't expecting such a strong response against the idea. I guess a big reason not to do it is that you might scare off potential employees! I have to admit that in my experience, an IQ test has proven to be one of the best indicators of future performance.

Answer 1

The very idea amazes me -- why would a company care about a programmer's IQ? Coding ability? Certainly. Problem solving? Of course. Communication skills? Definitely. However, IQ itself tells you nothing about what kind of coder someone is.

Answer 2

Well I wouldn't go any further with the application process if I was asked to complete an IQ test. I've also been asked to complete 'personality tests' that claim to evaluate 'team fit' or 'leadership style' which I think are Bad News (tm).

I have no problem with programming tests.

Answer 3

Absolutely not. IQ has little or nothing to do with whether they will be a good employee.

I would say the most important thing in the process is making sure there is good chemistry between the prospective employee. As a close second is their level of skill. Programming can be taught, tuned, and crafted with most people, social skills and good chemistry cannot.

A great way I have seen (and used) to test chemistry is to take the whole team out to casual lunch with the prospective hire (after completing all other competency tests) . See how the group interacts, and if the hire is comfortable among his possible peers. Keep in mind there will always be nervousness, but the hire should be able to cope with good natured jostling and overall 'fit in'. This also gives the prospective hire a great opportunity to decide if they like you and your team, and whether you are the kind of person they will want to work for. It also lightens the mood in what can be a nerve wracking process for people.

Answer 4

I believe some of the tests that programmers are put through during an interview can be unfair. I've been on interview where I've been asked to solve a problem or write a block of code. There arn't really any other fields that are put through that kind of interview process.

I wouldn't rate IQ tests very high; certainly not higher then education and experience. IQ tests arn't always 100% accurate and sometimes don't show a persons full potential.

Answer 5

IQ tests are a notoriously poor way to gauge ability or aptitude, especially in any particular vertical domain. I think it's widely held that there are many different kinds of intelligence and that I tests only test one particular type of ability.

IMO you'd be much better off with tests of the specific abilities you're interested in gauging (perhaps in the form of performing a sample task) rather than something as limited as an IQ test.

Answer 6

I've encountered trading companies using polygraph detector :) I wouldn't be surprised if some IT company conducts IT tests. IMO IQ test has nothing to do with programmer proficiency. IQ > 190 won't make anyone good programmer.

Answer 7

IQ tests are not really an accurate measurement of intellect and therefore their results should be taken with a grain of salt.

They are also very language-specific, i.e. if you will interview non-native English speaker with an English IQ test the results would be significantly lower that they should. If you will give them a test in their native language you will have a problem with translating the results (they do not match 1:1 between the versions)

The last but not least is that quite often you do not look for the traits exhibited by people with very high IQ test results when hiring programmers and you will get much better results from just talking to people.

Answer 8

IQ tests aren't actually entirely reliable to begin with - it's certainly not an unambiguous means of assessing intelligence.

Secondly, somebody could be a genius at mathematical/logical areas but entirely awful at language problem solving and score low, yet may well be the ideal candidate for the job. Stress could play a part too and ruin performance.

You're better off umm... seeing whether they can program well :-) FizzBuzz first to weed out those who can't program at all.

Note high score on IQ test != good at programming.

Answer 9

I have interviewed a lot of developers and I have never used an IQ test. It's quite hard to administer this sort of test in an interview situation, because a person's performance can be affected by their cultural background, education, age and various other items. As such, even though you're using a standard test, you will not get standard results that you could objectively compare to one another.

For example, you could have a genius from India whose grasp of English and local cultural concepts causes him to score lower than an average Joe from your home country.

Having said that, I believe there is value in gauging whether someone is generally intelligent. This is half of the famous 'smart and gets things done' criteria that Joel has espoused in the past. You should look for high scores in university courses, or other indication that the person is head and shoulders above the crowd, such as industry awards or challenging extra-curricular interests such as high level physics, engineering, etc.

I would rate intelligence highly, as intelligent people tend to:

a) Have the ability to understand topics or subjects quickly and easily.
b) Excel at skills they have been involved with for a long time.
c) Have good general understanding of a wide range of fields.

Having said that, you need to balance this trait against the other half of that famous meme: 'gets things done'.

Look (and ask) for situations in which the person demonstrated initiative, stepped outside the strict bounds of their position to contribute at a higher or broader level to the success of their organisation. A good example in developer circles is looking for people who have taken the initiative to develop internal tools to improve the efficiency of internal processes.

As far as I'm aware, there is no legal restriction on presenting an IQ test at interview, at least not in Australia.

Answer 10

In the US, I think there are actually legal restrictions on written tests. You may want to consult with HR before doing it.

A better approach is the verbal programming question. Do this in two parts:

1) Ask the candidate to write an utterly trivial program (something about 5 lines long that involves a loop). This is so you don't have to spend 40 minutes watching incompetent candidates try to figure out question (2), which is always painful and awkward for everybody.

2) Ask the candidates to solve a simple problem involving either pointers or recursion. Basically, you want an easy homework problem from halfway through an introductory data structures course. Maybe 10% of otherwise qualified candidates will answer this on the spot; the other 90% will flail and take forever. Good questions include: Tell whether a value is present in a binary tree, reverse a linked list, or count the words in a C string. Choose whichever programming language is top-most on the candidate's resume.

I've found that programmers who can answer (2) turn out to be much stronger on the job, because they actually remember their CS degrees, and they can reason through problems that involve multiple layers.

Answer 11

NO! It indicates a profound misunderstanding of what IQ really is. The IQ test is designed as a way to predict performance in school, and as such it does very well. But beyond that it's misleading, especially for people who are past school age. IQ stands for "Intelligence Quotient", and the "Quotient" part is because you take the base score on the test and divide by the test taker's age to get the final score -- it's the result of a division operation. As you get older this approach just doesn't scale well. Anything over 22 and the results start to skew downward because you just can't score high enough to compensate for your larger divisor.

Answer 12

An IQ test only gives one possible measure of a persons intelligence. And even that measure is highly sensitive to the candidates mental state at the time of testing.

Also any test can be affected by practice, as in the story of the schoolboy whose father designed intelligence tests and was mistakenly considered a genius for years because he did them for fun in the holidays.

There are hundreds of tests used to assess different measures of intelligence, such as spatial awareness for fighter pilots. It might be possible to pick tests to assess adeptness at manipulation of abstract concepts, but why bother when inviting a candidate to pair program for a day does the same plus much more?

Answer 13

Since IQ is a method for determining your mental age, I dont see how a specific task like coding would show any difference with brain power vs say a task involving tying your shoelace. I was given a IQ test back in my military days, they said I was as dumb as a rock. I knew back then I'd make a good coder.

Answer 14

Nope.

Say you went through with the IQ tests, how are going to use the results? Must score between x and y?

How would the test result help you in making your decision between candidates? What if two people had the exact same score? What if they were only a point apart? You will most likely have to 'fall back' on another set of criteria, like interview performance.

Adding this test would just further complicate things; KISS! Unless... you like wasting time and money.

Answer 15

IBM has each interview candidate take thethe 90 minute IPAT (Information Processing Aptitude Test). This apparently helps them figure out the strengths and weaknesses of the candidate.

Answer 16

go right ahead - but don't use it as a sole indicator, as some people are very bright but do not test well. And don't be surprised if a lot of people bristle and bail when you mention it.

the last place I had to take an IQ test also gave me a personality test. These were for general employees, an HR requirement, not specifically for developers.

The IQ test result was "off the chart", and the personality test result was "creative perfectionist".

Duh. What else would one expect from a programmer?

Answer 17

For me this is a clear cut issue. A high IQ rocks … however ... if its gonna scare your prospectives away ... Dump testing for it. If your algorithms are related to one ground breaking concept of “relativity” after another, then it might be essential to test for it, but if raw brain power (vs. Programming Skill) only comes into play 1% of the time, then what is the point?

Much like insisting that a security officer (whose chief duty is to spot the problems from the air and radio a ground crew to execute the arrests), be as physically fit as possible. Requirements should fit the work spec. And, usually, the "stoichiometric" ratio of IQ vs other job related attributes, is such that IQ is a (surplus) or non issue for most programmers.

However ... it's worth repeating: "High IQs Rock!” If you programming on the cutting edge of Math, AI and Physics then high IQ could arguably be shown to be a weighty KEY ingredient. The word ingredient is in itself key. The recipe requires all the key ingredients. Your job spec (recipe) should dictate the minimum required quantities of each ingredient including IQ.

BTW: (1) I am VERY humble, (2) My IQ must be extremely high because, try as I may, I just cannot access the darn thing (3) I used to be conceited but now I'm perfect ... Did I mention humble? (4) My dear old wifes response to this lengthy posting is: “Brrrrrr you’re borrring”

Answer 18

lol u guys are fools i use one in my interview process and i have the most amazing talented team ever they have made me wildly wealthy

Answer 19

I took a IQ test at http://www.iqtestforfree.net and score 128.

Is this Ok and why?