Intelligence is considered key to solving all types of problems. Crystallized intelligence is the ability to memorize facts and retrieve them when dealing with a problem. Fluid intelligence is the ability to go beyond simple retrieval and use creativity and pattern recognition to come up with solutions to more complex problems. Both types of intelligence are measured in standard IQ tests, which have been around for over a century.
Administrators of the IQ test have noticed a pattern through most of the 20th century that IQ has been going up. While the average score of 100 has never changed, raw scores on IQ tests have gone up regularly, requiring a re-calibration of what it takes to be average or exceptional. Scientists generally attribute the rising scores to improvement in education, nutrition, medical care, and mental stimuli throughout the 20th century. Our more affluent lifestyles had made us smarter to boot.
Now researchers are seeing that IQ scores have actually been headed down for the last 20 years or so, and no one seems to know why. The trend was first spotted in Scandinavia and has been noticed in Europe and Australia, where education systems are highly rated and statistics are kept and analyzed most. The trend has not yet been noted in the United States, but very little research has been done here on the topic. Science, intelligence, and critical thinking have not been as much in vogue in US popular culture for much of the 21st century.
So what could be causing the drops in IQ scores? Some are blaming immigration of less intelligent races into countries experiencing drops, but that was disproved by Norwegian studies showing the drops occurring in the same families. Some blame dumb people for reproducing faster than smarter people, which is also not supported by evidence. As much as easy answers about inferior people appeal to some, most theories involve the changing environments of the schools and workplaces.
Since the rise in IQ scores of the 20th century, called the Flynn effect, was likely caused by environmental factors, the decline should be also. Certainly there is no shortage of suspects for the things that are making us more stupid.
The main question remains whether the causes are biological or behavioral. Many new chemicals have been introduced into our environment in the last 50 years, any one of which could be altering brain functions. Heavy metals and toxic chemicals are found in our water systems, soil samples, food and in the oceans. The advent of the wireless age means that many more invisible waves are being transmitted through and around our bodies, the effects of which aren't known. Environmental pollutants have also been suspected in other mysterious cases such as the rise in Autism rates or the decline in male fertility. There's a lot we just don't know.
A more likely culprit for the world dumbness epidemic is behavioral. The educational system and at the workplace are becoming more ruled by algorithms. Repetitive tasks are more common for humans as machines take over the creative, problem-solving thinking. In evolutionary terms, if you don't use it- you lose it. And we haven't been using and stimulating our fluid intelligence as much as we had in the past.
My own pet theory is the information overload effect, detailed on this blog in The Ping Pong Ball Blizzard, could be to blame. Perhaps the glut of information since the 90's has shorted out our brains and hurt our ability to process information. Certainly the decline in political discourse points to a decline in the value of critical thinking and intelligence. If this were the case, you would see an acceleration of the decline every year, and data just isn't available to prove that.
So should we be concerned about this? Maybe. We definitely need to keep an eye on it, because computers can't be trusted to do all the thinking for us. Plus income inequality would certainly get worse if there were one superclass of geniuses and one of dolts. More data and research is needed.
And before all the smart people start feeling superior, let's remember that raw intelligence doesn't necessarily make you a good person. Honesty, integrity, empathy and kindness are more valuable than pure intellect. There have been many evil geniuses through history, maybe not as leaders, but enabling authoritarians and corporations with their brainpower and ideas. A third type of intelligence, emotional intelligence, is not measured on IQ tests, but the ability to sense feelings of others is more important than memorizing the periodic table.