Intelligence, as measured by IQ, has been - since the middle 1960s, when it became the first, and still the most aggressively persecuted, object of political correctness - prone to a tremendous amount of misunderstanding in both directions: under- and over-valuation. Indeed, some of the honest (albeit ignorant) undervaluation of IQ comes from reacting against those who overvalue it.
(Of course, most of the undervaluation of intelligence is simply dishonest as well as ignorant: invincibly ignorant, in other words.)
The fact is that IQ test measurements are only modestly precise, modestly predictive, and thus only modestly valid, at the level of individual people. But IQ scores are highly valid and reliably predictive when used to compare group averages. (H/T to Steve Sailor for making this clear to me.)
So, when outcomes are measured in terms of educational success, job status, social class, income, health, life expectancy - a group of 200 people with average IQ of 130 will (pretty much) always significantly outperform a group of 200 with with 115 average IQ; but the same certainly does not apply to individuals.
Personality is very important as well, albeit personality cannot be measured in the same way as IQ; but is only evaluated by human beings (self, parents, teacher, employer etc). A more conscientious personality will provide much the same outcome advantages as IQ - but (at least within races) there is very little correlation between personality and Intelligence.
In particular, there are plenty of high IQ people with low-Conscientiousness personalities - and low-C is quite sufficient to negate any IQ advantage in modern society. I have met several de facto 'unemployable' people with very high intelligence, and indeed such people tend to form the nucleus of the high IQ/ ultra-high IQ societies.
But there is also a confusion about the role of intelligence in creativity. In a nutshell, high intelligence is necessary but not sufficient for creativity; and most highly intelligent people are not at all creative. This can be seen most clearly in the study of creative genius.
In saying this, I am talking about real, primary creativity - not simply what passes for creativity in the superficial and dishonest modern world; which is mostly about expropriation, extrapolation and recombination of already-existing ideas: the kind of 'faked' creativity seen in high status advertising, design, illustration, modern art and sculpture, professional research (so-called 'science'), popular music, mainstream journalism, cultural criticism and theory etc.
Yet it is quite common to equate high intelligence with high creativity; and not to notice that extremely high intelligence is usually absolutely un-creative. Mental speed usually goes with mental dullness/ conformity.
And this applies especially among the high intelligence/ high conscientiousness people (the Head Girl type, as I call them; of both sexes) - who are those most likely to achieve high levels of education, wealth, status and power.
Indeed, in modern conditions, while high success in the social institutions (including 'science') is possible for those of high intelligence, creativity is extremely rare; because only the most Conscientious/ least creative can thrive in these environments. High Conscientiousness is mandatory, but (even in the elite colleges) high intelligence is subject to compromise.
Meanwhile the most creative people are often more modest in IQ, highly intelligent, but not usually among the highest; and among those high in IQ the most truly-creative are low in Conscientiousness (because inner orientated and directed), and therefore tend to number among the (relative) social-status mediocrities or even failures.
So, even if someone has a very high opinion of himself; there is no reason why he should be touchy, eve paranoid, about his personal, individual, measured IQ; no reason to assert that he is more intelligent than you - no reason to assert that those he admires are more intelligent than those he despises: firstly because such measurements are imprecise; secondly they are poorly predictive...
And thirdly because, when it comes to The Most Important intellectual attribute - genius - intelligence is only one part of a package that must also include an internally-aware and self-motivated - hence low Conscientiousness, hence typically status-failing - personality.
*Note - "Paranoia" is defined here as the combination of heightened self-awareness with heightened self-reference (in short: Everything is about me).