In our disposable world of high technology getting ever cheaper year by year, we feel a lot smarter than our forebears ever did.  We have access to greater tools and more information in less time.  I was just reading a June 1969 issue of LIFE magazine and an entrepreneur was talking about creating terminals that would allow you to ask any question and get the answer back on your screen, all ready to go by 1975.  It took a lot longer than 1975 to get there, but now that we've arrived, all of can gloat at the 1969ers or 1975ers for how primitive and uneducated they were.

Scientists can back that belief up to some degree, with what is known as the Flynn effect.  It has been observed that scores on IQ tests throughout the world have been going up continuously over time.  Ulric Neisser, author of The Rising Curve: Long-Term gains in IQ and Related Measures, says that relative to the average IQ levels of today (100), the average IQ level of the United States in 1932 was only 80.

Cultural factors aren't the reason.  The IQ improvements are noted with infants and preschoolers at equal rates to older students and adults who've already had plenty of time to become acculturated.   Perhaps nutrition and a change in cranial vault size lead to the improvements, yielding the IQ boost at the very youngest ages which is then maintained throughout the person's lifetime.   More stimulating environments and better schooling help, too.  Even terrible schools of today would've had to benefit from more advanced learning materials and techniques compared with terrible schools of the past. 

There appears to be a limit to these gains, however.  In developed nations, there've actually been decreases.  British fourteen year olds from 2008 scored more than two points lower than fourteen year olds from 1980.    The young Danish male IQ rose slightly from 1988 to 1998, then decreased until 2004.   So which is it?  Are we progressively getting smarter, dumber, or reaching a plateau as a population?

IQ tests purport to measure general intelligence, known as the g factor.   The g factor is the correlation between the testing of different types of intelligence --  in verbal skills, reading, abstract reasoning, math, spatial awareness, vocabulary, memory, basic knowledge about things.   To be considered highly intelligent, you need not be a star in all categories.  You could possess a very broad vocabulary but be poor at math. Nonetheless, the correlative effect seems to indicate that someone testing high in memory retention is likelier to have higher math scores, a better vocabulary, and more knowledge about the general world. 

There's been a debate for over a century over whether heritable factors or environmental ones contribute more to intelligence.   There's little question environment plays some role.  A child raised in a stimulating environment and eating nutritious food is going to score higher on an IQ test than if the child lived in a hostile and malnourished environment.  But what's new there?  That's like saying a runner is going to run faster and better if he has a better coach and eats a healthier diet than if he doesn't.    Superior training and tools will always lead to better results, but only relative to oneself.  Another runner born with a higher VO2 max rate than you, using the same superior training and tools as you do, is going to outrun you.

The genetics vs environment studies have been performed already.   Siblings brought together through adoption show the same correlation in IQ as they would to a man on the street, whereas blood-related siblings display IQ's significantly more closely related; and identical twins, almost identical ones.    So let's leave the nature vs nurture debate out of this entirely.  You can assume, if you like, that certain environments lead to smart people or that it's the parental genetic code that brings it all about.  It won't affect this discussion.

In 2002, Dr. Richard Lynn wrote the book IQ and the Wealth of Nations.  His argument is that average national IQ is one significant factor in the economic growth and wealth of a nation.   High IQ alone doesn't cut it as a wealth indicator, he observes.  Mongolia and Norway are both tied for #19 on the list.  Norway is one of the richest countries in the world and Mongolia the poorest.   Natural resources and the economic system in effect play a role, too.

But as a whole, if you can get past the way Dr. Lynn computes national IQ's, the nations scoring at the top of the national IQ heap are all rich ones or quickly developing ones.   The nations scoring at the bottom are economic losers.  The rich exceptions in the low IQ realm, like Botswana or Saudi Arabia, have resources the rest of the world lusts after.  

However you believe intelligence is passed on, either by environment or heredity, less intelligent and less successful people and nations produce more offspring than rich ones.  The negative correlation between fertility and IQ is not a new discovery.  The Democratic Republic of the Congo has a birth rate of 49.6 (per 1,000 people), Nigeria 39.9, and Equatorial Guinea 38.5.  Their respective national average IQ's are 65, 67, and 59.  Compare that with low birth rate Japan (8.3) , South Korea (9.3), and Hong Kong (7.6) with IQ's of 105, 106, and 107 respectively, the three highest in the world.   You don't have to be good at math to figure out what's happening.   The dumber poor are massively outbreeding the smarter rich. 

To illustrate, imagine a classroom taking an examination.  There are ninety-nine students in the classroom to start with.  The teacher grades the exams and the average score for the class is 50%.  If a hundredth student is added to the class, for the average classroom score to rise, this new student must score above 50%.

If you think of all the globe's nations contributing additional students to this world classroom based on their relative population growths, Nigeria, Congo, Equatorial Guinea and their like-minded brethren will be submitting a helluva lot more students than brainy Korea, Japan, and Hong Kong.   For every one student Korea adds to the classroom who would improve overall class averages, Nigeria adds four more below average students.  Over time, the raw classroom average keeps falling.  The only way this wouldn't hold true is if intelligence is purely a random trait, that all people, regardless of their native intelligence, are equally likely to produce geniuses or idiots.  No data supports that conclusion.  Heredity and environment each play a role, the exact amount open to debate, and neither are random.

You can scoff at the methodology of the  IQ and the Wealth of Nations and the whole idea of a national IQ.  I used national IQ's as a simple illustrative device.  They don't affect the conclusions.  Smarter people reproduce less.  That's part of the reason they're smart.   Kids cost time, money,  and energy, and smarter people have more of all with less kiddies. 

These falling intelligence levels are hidden from view because IQ is graded on a bell-shaped distribution curve, with the median always set to 100 and a standard deviation (usually) of 15.  But this is all relative, isn't it.   Someone two deviations above the median always has an IQ of 130, even if on some absolute scale the number may not mean what it used to. 

Doesn't the falling average argument contradict the aforementioned Flynn effect of IQ scores rising over time?  Not necessarily.    Think of a test like the Scholastic Aptitude Test (SAT), the standardized test taken by American high schoolers for entrance to university.  Aptitude is defined as a natural tendency to do something well.   It's something you're born with.   In theory, you shouldn't be able to study for the SAT and improve your score. 

Believing this, I took the SAT without preparation two-and-a-half decades ago and obtained a decent score.  My brother took it a year later and didn't.   He enrolled in an SAT preparation courses and retook the test six months later and earned a 150 point gain.  Five years later, I took two more standardized aptitude tests -- the Graduate Record Examination (GRE) and the Graduate Management Admissions Test (GMAT).  This time I bought preparation books and, on my own, reviewed them 2 months in advance.  My scores were far, far better than decent this time around, one hundred points short of perfect on both.

It's been documented that if one takes the same test over and over again in a narrow time frame, his scores will always fall within a very narrow range.  These tests do accurately measure something, whatever that something is.    So how could my brother and I have seen such improvements if all these tests were aptitude tests?

Because preparation always leads to improvement.   All of us are born with a certain potential.  We may only actualize a percentage of that.  I'm not currently a great tennis player.  If I practice every day for eight hours, I would invariably become better.  My biggest improvements would come at the beginning, with only marginal improvements later.  In time, my actualized results would approach my innate potential.  After a number of months of practice, a professional tennis coach would be able to judge on the spot whether or not I was "a natural."  Even with all that practice, the likelihood of me becoming as good as a Roger Federer or Pete Sampras is near zero, as evidenced by the fact that just a small percentage of players ever enter the professional tours. 

There's a ceiling, too, on how high on a college entrance examination or an IQ test one can score.  A dim witted person can study for the SAT or an IQ test for years.  He'll probably improve a few points, but he'll never score a deviation above the mean.  My brother's and my first forays into standardized testing did not yield our full potential. Only some preparation unleashed it. 

And that is my point.  People taking IQ tests 80 years ago, due to nutrition, the educational system, cranial vault size, or whatever, were not taking those tests at the same unleashed potential as testers today.   Their results were as accurate as my brother's first SAT score.  Today's system slightly better activates the abilities that are measured on these IQ tests. 

But as the actualization percentage of potential intelligence has gone up, the numerical value of average potential intelligence, which has never been truly measured, is dropping and has been ever since the world's population exploded after the industrialized era began.  As a whole, we're getting a larger room in the house, but the overall size of the house is getting smaller. 

The decline in overall intelligence is almost imperceptible.  Technology brings more tools to more (dumber) people and skill sets become more specialized.   It is drilled into us to do one thing and do it right, like Kentucky Fried Chicken. "We do chicken, and we do it right" one of their old advertisement campaigns chimed.  Modern economics has proved that specialization of labor makes all the trading parties richer in the long run.   There's no room left for the Renaissance Man, for what is a Renaissance Man but someone who has potential in a lot of areas and has actualized it? 

The stage has changed.  And with its more flattering technological wonders, we don't realize we've become dumber.   Our wonderful mobile technologies that people just twenty years ago could only dream about distract us from the fact that now most of us have attention spans no longer than 5 minutes.  Convenient and free to-the-door deliveries distract us from  the fact that most of the food we consume has very little nutritional value.   Transportation advances and discounted deregulated airfares distract us from the fact that few of us walk or exercise at all anymore.   We think technology will take care of us, as most of us, dumbed down by breeding and by IQ-destroying passive entertainment (TV, YouTube, 24/7 online gaming), lose the ability to fend for ourselves.