[Icelander]

Yeah, GURPS IQ is how well a character does at tasks that are IQ-based in GURPS. That's a much wider field than anything measured by real-world IQ tests.

Trying to establish some metric of converting between them is kind of pointless, sort of like trying to establish details about elephants by what a blind man can tell by feeling their trunk.

In general, real-world IQ measures the ability to take standardised IQ tests and not really that much more. Plenty of people who score high on IQ tests do not go on to enjoy sustained success in life, for one reason or another, and the correlation between high measured IQ and success at a wide range of tasks that GURPS makes IQ-based is extremely weak.

In GURPS terms, someone who scores astronomically high on IQ tests, but has problems with actually accomplishing stuff has IQ around 10, probably some Disadvantages and a Hobby Skill in taking IQ tests, along with maybe a few Perks that help with it (I'd allow Hyperspecialisation, for example). They may have Mathematical Ability, but only if they actuall have a functioning professional skill level at several skills under it.

GURPS IQ, on the other hand, does not represent potential or theoretical intelligence. It represents actual, functioning ability to succeed at IQ-based skill checks over a sustained period. As such, the best metric to use to benchmark from GURPS IQ to real people to vice versa is actual accomplishments at tasks that fall under GURPS IQ.

If someone is an expert at several related IQ skills (say, like maths or science), but isn't necessarily good at unconnected IQ-based skills, like Administration, Diplomacy, Merchant or Propaganda, to promote themselves and get funding, they probably have a Talent and IQ at 10-11.

Very few people famous for high real world IQ would rate high GURPS IQ, simply because most of them have very narrow fields of expertise and do not also demonstrate above average social skills, investment savvy, teaching ability, organisational ability, etc.

Someone who is very good not only at their specialsation, but also at many other IQ-based tasks, like someone who is a scientist, self-promoter and media personality, is widely popular among peers, good at arranging things and running organisations, etc., that's a candidate for high IQ.