Why can't success be a measure of IQ?
Quite simply, people want to be smarter so that they can have an "easier" life or be able to overcome obstacles they currently cannot solve.
I don't have a strong opinion of my own intelligence. Although assessing the intelligence of others is a hobby of mine given how it is a necessary part of management. I also have a growing idea after reading books about game theory, predictably irrational, articles on psychology related to problem solving, memory, skills, attention and concentration.
Personal Disclaimer: I believe we have a mixed bag when we try to measure intelligence. Game theory helps bring some clarity for some matters because it sets an important assumption: Motivation and Rationality. This coupled with psychology and human observation (a first and important step in an empirical understanding) leads me to believe that like military training, 90% of all people can be honed and trained to exceptional levels.In GURPS, you cannot do much intellectual stuff with IQ10 because the way the system implied to be executed has some flaws. Particularly, the mechanics surrounding the application of defaults. I'm a stickler for defaults, and it made an IQ10 character a relative genius.
This has something also to do with how people view empiricism as actually a choice and not a rational extension. Which i wont go any further on because it invites too much debate.
Mentally identifying all your own assumptions is an important mental discipline that is rarely taught or hardly encouraged except in the fields of problem solving and science. What typically happens is that assumptions are usually made that many actions have no relevant skills. So most of the time people roll default IQ10 a lot. If you applied defaults more meticulously, you realize the rolls are usually made with a -4 to -6 (an effective skill of 6 to 4 at 10% to 1% chance of success).
Taken further, rarely is there an understanding of what a skill entails in GURPS. There are many books of particular real world skills that are found in GURPS. In these descriptions and books, you will note a pattern on what is Routine (+4 or +5 to the roll), what is standard expected challenges with an acceptable level of risk for a professional (skill 12, Task difficulty modifier +0), and what is considered hard and mostly an unexpected complication, which usually is considered to risky to venture, falling in the task difficulty modifier of Hard to Impossible.
So a skilled person doing a Routine action will have a 13-15 (80-95% chance of success), while someone unskilled will have a 4-6 (1% to 10% chance to succeed). Note the huge gap. This is because someone trying to do something they have barely a clue, assumes that a clue is enough in Murphy's domain.
That is why even the most trivial actions are drilled into soldiers and professinals, because every little bit matters and increases the chance of success.
1cp means trained, it means the person has spent 800 hours doing this on-the-job, 400hrs practicing it by himself, 200hrs in skilled tutelage, or 100hrs exceptional training. 1cp is no small thing, it can mean the difference of up to 94% chance of success.
What has this got to do with success?
One of the things I learned about game theory is how strategies work with Murphy hanging overhead. Particularly, the role of adaptability. Well rounded characters are realistically very successful. Because given the certainty of a Murphy, having as many alternate strategies available spells a very great difference in odds.
How about the roles?
Roles in games stopped being Flanker/Striker, Blocker/Tank, Leader/Support, and Controller for me because it ceased being about combat and more about problem solving. This happens to be emphasized because of my accessibility to real war game simulations.
Roles in management (try not to immediately equate this to boring, if you don't like the term use dynamic organizational interaction) a team is not exclusively defined by a role, but instead adapts to what ever role is needed of him/her in a given situation.
Opportunity is harder to predict and has the greatest the strategic influences because of the advantages a group is taking. Control is not about trying to Predict Murphy, but looking for Murphy's chinks and adapting to that. Coupled with well rounded skill set, taking advantage of what ever opportunity has more devastating effect.
Bottom Line, intelligence.
So an IQ 10-11 person with the right adaptive skills will be more formidable than a IQ 12-13 individual a 1/3 smaller set of skills because he has more options and more strategies to pursue. Of course there are points of diminishing returns and optimal trade offs depending on the GM and certain assumptions.
The reason why GURPS IQ doesn't really work as a measure of success is because in the end, it is the player's own IQ that determines the success and failure of the character in a Game Theory point of view. A more strategic player can do much more with 100cp than someone less adaptable.
In Role-playing, IQ10 person can sound smarter than the IQ12 person if the IQ 12 didn't take public speaking, literature, and acting.