Intelligence. Is it malleable? Heritable? Can it be measured reliably? Is IQ the golden standard? Does it predict people's success in life? Is conscientiousness more, equally, or less important than intelligence?
Human intelligence is, perhaps, one of the most interesting issues debated today. In an age where "each person is unique just like everybody else" but, at the same time, the divide between those who have it all and those who don't has widened, few people know what to make of it. To illustrate how spiky the subject is, let me tell you what intelligence is in dogs. Stanley Coren, a psychologist who seems to like us more than humans, coined a canine intelligence measurement based on our ability to do what we're supposed to do and to learn from humans. So, for example, the less repetitions of a new command needed before we do it, the "brighter" we are.
In humans the issue is not that different, really. Intelligence is seen as the "muscle" needed to absorb information, generate concepts with it, break it into little pieces, put it back together logically, and apply reason so, through the recognition of patterns, store data, use it to solve problems, and share new information with others. Hubristic as humans are, the reality is that bringing you the newspaper in the morning, on command, is pretty much the same, all proportions considered, of course. Under that base, since the early XIX century humans have been developing more and more accurate tests to measure such capabilities. As the world is geared in like that, intelligence has turned out to be a very good predictor of educational success and occupational status, hence of income as well. And for anyone trying to add nuance to the concept, likely moved by a compassionate agenda (which usually turns into totalitarianism), just ask them: if given the chance, would they rather be born with an IQ of 60 or with an IQ of 120. Issue settled.
But then we have the other great predictor of outcome in life: industriousness. What puzzles humans the most is that there is no correlation between intelligence and the ability to plan long term and then carry out plans, i.e. being diligent and hardworking. While there are exceptionally bright people who won't let go off the PlayStation™ controller until their late 40s, there are less bright individuals who just keep on grinding and end up conquering the greatest obstacles. The strongest predictor of failure, then, is being dumb and lazy. Not precisely rocket science but grandma wisdom, isn't it? The extremely polemic issue here is how much is out of people's hands, though. Yes, IQ can change. But the changes are neither dramatic nor stable. It boils down to effort in that sense, bringing us back to industriousness. What is most shocking, though, is what is not in everybody's hands, or at least not easily. A person's face influences higher earnings, for example. Most dramatically, winning in the sperm lottery plays a big role, and by that I don't mean being born with a silver spoon but with educated parents. And having both of them.
This brings me to the most important part of this whole debate. Yes, everybody would prefer to have a higher IQ and, by all means, achieving both material success and the esteem of one's peers is more likely than not to bring life fulfillment. IQ is *a* thing and not a "social construct created by the patriarchy" in order to oppress the snowflakes. Nevertheless, I want you to take a step back and think about the reason for human action. People are goal oriented. They do what they do for something rather than just because. If the point of life is meaning, then what you'll see all the gurus peddling is a c-c-c-c-c-combo breaker of: (a) physical and mental well-being, (b) belonging and recognition, (c) doing something that is valuable, and (d) spiritual connection. Even I, in these pages, spoke about meaning as a result of having a more or less consistent worldview so as to decrease the psychological pain arising from dissonance.
However, I want you to consider that it may all be about expectations. If you expect to get a car and you get a bike, the disappointment is more than if you expect to get a red bike and you get a blue one. If you want to eat, a boiled potato may not be a gourmet feast but it satiates your hunger, while expecting a buttered lobster and getting a potato is certainly a letdown. People have, I have noticed, inflated perceptions of themselves. They want it all but aren't willing to work for it or, simply, don't have the chops.
Look at the matrix right here. A lazy and unintelligent person is pretty much screwed. But, what if that person is content with what life has in store and envies absolutely nothing? I'd say that such a person has it made. His is an existence that, perhaps, may be unappealing to you but it would be satisfactory for the person. Being unintelligent but industrious is a double plus, i.e. a sure way of increasing one's chances of reaching goals that are susceptible of partially becoming reality by effort. On the other hand, an intelligent person who is simply lazy has the advantage of, by sheer brightness, have something fall from heaven and land on her lap. The best of all the possible worlds is to be intelligent and industrious, no doubt about that. It is guarantee of nothing but it is probable that plans will be drafted, pursued, and more or less achieved, reaching both the esteem and admiration of peers as well as the satisfaction of overcoming. Material comfort and mate choice will follow. However, all this goes to the trash bin if the person has expectations beyond what it achieves or, at a minimum, cannot handle the disappointment of the dicey hand life is known to deal.
In such a scenario it does not matter if one is intelligent or not, industrious or lazy. What matters is expectation management. I am not sure how to call this but, frankly, it is not intelligence in the proper sense of the word. I hesitate to theorize in this regard, mostly for fear of failing in the same manner that the charlatans of the self-esteem wishy-washy, feel-good hogwash. No, there is no scientific support for the multiple intelligence theory that talks about different ways of being smart and that they move independently from each other, sorry. I know it supports the feel good thingy that there are no people more intelligent than others but merely different. It is empirically impossible to measure the supposed other types of intelligence and the attempts to develop a systematic measurement have shown the variables to be correlated. Now, that does not mean that there aren't important non-cognitive abilities apart from general intelligence, but those are already recognized and they are called skills, e.g. effective socialization, good judgement, or applying well whatever little one has in the toolbox.
I believe that it is in wisdom that success exists in an agnostic enough manner, and by agnostic I mean substance and contentment but without passivity. As one gets older, the realization is that money is important but just to a point, and that being a hippie is as immature as being a greedy bastard, so I wouldn't remove economic success as a proxy for success. However, it is blind to leave it just to that. It is a herculean task to define wisdom but from the attempts made I wish to keep the one saying that it may be a mixture of commonsense, insight, and prudence. The combo of these three traits grants the capacity to judge right in matters of life and conduct, and by doing that a person knows how to lead a good life. At the end of the day, existence isn't about happiness but having more arguments to continue existing than not.
Whether one has a decent IQ or not, the best is to develop useful life skills and habits of industriousness. Moreover, it is wise to regulate ambition so as neither to lack nor to be dominated by it, and whenever fortune or misfortune strike (as they surely will from time to time), it is prudent to surf the wave with aplomb and levelheadedness. That said, being intelligent never hurts. It is commonsense.