Here are a few of the blogs (along with The Bell Curve) that I read to educate myself on the subject of IQ and cognitive ability.
https://educationrealist.wordpress.com (to a smaller extent; most of the writing here is about education)
Of course, there are many more blogs on the subject, but it is difficult to list them all here without going a bit bonkers. Besides, the entire collected oeuvres of these bloggers are enough to keep anyone occupied for years. For the reader that prefers pictures to words, most of these blogs are replete with plenty of graphs and charts illustrating the significance of IQ with respect to some factor (and since IQ is so important, there are lots and lots and lots of such graphs and charts).
The Importance of IQ
I’ll keep this short, since the blogs I have already listed go into far greater detail on the subject (and more eloquently than I ever could).
The first question we might ask ourselves is, “What does it mean to be ‘smart'”? What do these things called “smart people” do that these other things called “dumb people” do not do, and vice versa?
As you have probably noticed in your every day life, the habits of successful people are far different from the habits of unsuccessful people – and I mean “success” in the broadest possible terms, for a broad number of different tasks. Think back to your time in school – some of your friends just couldn’t get the hang of the course material no matter how hard they tried. Let’s up the ante further on the success scale: what separates the multi-billionaire hedge fund manager from the unemployed felonized hoodrat? Why do some people become cannon fodder for the infantry and others become generals? Why do some people become engineers and doctors and lawyers, while other people are stuck slinging frappes at Starbucks?
Is it truly just a chance of birth that Mr. Big was able to become a hedge fund manager, whilst Hambone is stuck selling rock on the block? Why do these cruel hierarchies form? Why isn’t everyone able to do every task equally well?
The cruel, vicious, underlying truth is that everyone was born with a number. Not a barcode, and not your social security number – but an intelligence quotient (IQ). And it is this number that decides who rises and who falls, not only for individual humans but also for entire societies. The prospect for raising this number is bleak, beyond the mother having adequate nourishment during her pregnancy, and the child being well-fed during his or her formative years. This number will fluctuate a bit with age, but will eventually settle to its final value.
While small differences in IQ between two people are of little significance, large differences are very significant in terms of important variables such as criminal behavior, educational attainment, income, and wealth.
What Does This Number *actually* Do?
It is important to understand that IQ isn’t just some silly credential like a college degree or a Boy Scout merit badge. It repeatably predicts future performance, good or bad. Take public school (especially high school) for example. High IQ students have higher GPAs, lower discipline rates, higher high school graduation rates, and greater chance of attending and graduating from college.Low IQ students have low GPAs, have problems with the law, probably won’t graduate or attend college, and have high chances of becoming one of the two sets of second-class citizens in America: high school dropouts and convicted felons. High IQ people go on to typically live successful, productive lives. Low IQ people live lives fraught with police run-ins, unemployment, and pauperism. Observe IQ’s by occupation as well. Entrepreneurs of high intellect rake in even more dough: see here, here, and here.
Hell, even the US military uses IQ testing to sort its recruits into jobs they are most likely to excel at. The military has little patience for stupid people. Stupid people do stupid things in the military. They drop the grenade and throw the pin. They are more crime-prone, and difficult to discipline. They can’t learn to do their military job effectively. They accidentally fire on their own people. They smoke during ambushes. Aggressively using IQ testing to screen people out of high positions is how the military abrogates these problems. One wonders if in the future, if weapon systems will become so sophisticated, that only the far reaches of the right-hand side of the bell curve will be able to soldier effectively. I myself know very little about future weapon systems; it is generally pointless to read into such matters in my opinion, since the weapons only see the battlefield if the Pentagon agrees to pay for them; the rest wind up on the experimental scrap heap.