If you were on the terrace of the Beau Rivage Café with Albert Einstein and lightning struck, causing Einstein's IQ to double …do you think you would notice the difference?
What parent does not strive to help develop his child's IQ to its highest potential? High-IQ people are more productive and more creative. Intelligence is a significant determinant of a wide range of economic and social phenomena including educational success, socioeconomic status, and life-time earnings. Low intelligence portends unemployment, poverty, misery, single motherhood and crime. Since human capital, understood as the quality of the population – its literacy, skills and health – is a significant factor in economic development, national differences of intelligence can influence the competitive well-being of a country.
At no time in history has this been more strategically important than now. Today, in a context where countries compete economically, knowledge and the ability to manipulate this knowledge determine success.
The ability to process and interpret correctly information underpins economic and military security. This holds true even if an impending ecosystem collapse coupled with resource depletion (soil, water and fossil fuels) profoundly alters human social organization with political conflict. A small, intelligent army is easier to feed, marshal and deploy than is a massive infantry of idiots. Post crash, people will also need to be smart and resourceful to succeed.
What if you learned that for at least the last 130 years our collective IQ has been set on a steep downward slope?
The study of reaction time (RT) dates back to the mid-19th century. Francis Galton, an eminent scientist of the Victorian era, set up his famous Anthropometric Laboratory, where from 1884 to 1893 over 17,000 people were measured on whole range of physical, sensory, and psychomotor attributes. Among them was the simple RT to light and sound, which Galton proposed might reflect general mental ability. We now have strong reasons to believe that indeed simple RT measures correlate substantially with measures of general intelligence.
Numerous subsequent studies throughout the 20th century followed. Full analysis of Galton's enormous data began in 1980s with modern statistical techniques and digital technology.
The conclusions are striking. RT has worsened across the entire socioeconomic spectrum and in at least four out of five Western countries. A meta-analysis and a computed correlation between simple reaction time and intelligence in studies conducted between 1884 and 2004 gives a decline of 1.23 IQ points per decade – or 14 IQ points since Victorian times. Note that a loss of 14 points across the population is huge. Although an individual may manage to make a decent living with 14 fewer IQ points, those numbers and the trend they represent translate to very serious repercussions for a society.
While you might not easily detect the difference between a person with an IQ of 100 vs. one with 86, there are huge societal implications of a 14-point drop because of what happens to the two tails of the distribution, as shown in this graph, which models a drop of only 5 IQ points on a population of 260 million. Because of the shape of the curve, a drop of 5 points would increase the number of mentally retarded people (IQ less than 70) from 6 million to 9.4 million… a 57% increase. And there would be 3.6 million fewer gifted people (IQ greater than 130).
Of course, there are data that don’t fit this general trend. For example, some reports suggest that video games played today by kids actually increase their RT. Also, between the 1930s and 1980s, the average IQ score in the US rose by 3 points. In post-war Japan and Denmark, IQ test scores have also increased. (Although recently an IQ test used to determine whether Danish men are fit to serve in the military has revealed that scores have also fallen in Denmark by 1.5 points since 1998). The US may have experienced another uptick when industry was forced to stop adding lead to gasoline and house paint – a simple measure which added back several IQ points to new kids in a widely lead-poisoned society.
This rise in intelligence is attributed to improved nutrition, living conditions, education, and technology (the "Flynn effect") – thanks to which more people have been reaching their full potential. This however does not mitigate the fact that that potential itself has been declining.
There are a few possible explanations for the deterioration of RT.
The first, knee-jerk one, is that RT has increased because of modern diet and sedentary lifestyle. But studies don't confirm it: an adult British and an Australian one showed that overall activity level was unrelated to RT (Diet, however may be a factor in RT deterioration discussed below.)
The second explanation is the buildup of neurotoxins in agriculture, manufacturing and consumer products. Indeed, a great deal of research shows that RT is longer in people who have been exposed to concentrations of contaminants such as lead (added paint and gasoline) [e.g., Barth et al., 2002; Schwartz et al., 2001], chlordane (a pesticide), trichloroethylene (an anesthetic and solvent) and mercury (used in chemical industrial processes) and many more.
Of course, exposure to neurotoxins, such as lead or dioxins from the smelting and burning of organic matter existed well before our industrial revolution (1760 – 1840) reached inside the earth for fossil fuels on an epic scale, and before the synthetic organic chemical industry arose from the humble invention of purple dye (1856).
But whether or not the Romans poisoned their brains by lining water pipes with lead is less relevant to us than our current, exposures to significant and growing amounts of high volume contaminants. For example, just Bisphenol A, known to have neurological effects and capacity to alter brain structure, was produced in the staggering volume of 2.2 million tons in 2009. Compared to today’s scale, the past was but a minor prologue.
We may observe with dismay the proliferation of obese people, or gaze at charts showing a ballooning incidence of cancers, infertility or diabetes. But we don't see the subtle deformations of brains that the RT data indicates is occurring in parallel. Traditional toxicological tools used by regulators to detect neurotoxicity are ridiculously simplistic. For a long time the main approach has been to expose lab animals to a single substance to identify the highest dose they can survive and then dissect them looking for tumors, birth defects or other organ damage. Visual clues that the brain is messed up are rarely detected. If brain damage were to be detected visually, then there might be a follow-up using more sophisticated tools.
Meanwhile, many new scientific studies are indicating that the brain is likely to be the most vulnerable to endocrine disruption, in which chemical agents interfere with gene expression. For example, a number of contaminants disrupt thyroid hormones, which normally instruct specific cells in the fetus to differentiate and develop into a properly functioning adult brain. The effects can range from severe intellectual disability to a whole spectrum of mild 'sub-clinical' dysfunctions, including impaired inter personal relations that so many experience today.
The third explanation for the increase in RT is that the health of our population has changed – not for the better. Spectacular infant mortality reductions of the past 200 years allowed proportionately more people of less than robust health to survive into adulthood. There are data showing that such people have longer RTs. "Our longer life spans are proclaimed as modern achievement, but longevity and robust health are not the same things. Diabetes is a case in point. Although medication allows diabetics to remain alive and active, they are at risk of poor circulation, vision loss, poor kidney functioning, infections, nerve disorders and increased RT" writes Irwin W. Silverman in The American Journal of Psychology.
Basically, as Christopher Williams wrote in his prescient book Terminus Brain: millions of people are suffering a degraded intelligence and psycho-social skills due to pollution, further exacerbated by the rapid decline of vital environmental micronutrients (with the advancement of intensive agriculture) and the exponential increase of environmental contaminants. How fast is the change – one can only speculate but it would be naïve, stupid and dangerous to think that the waves of children born in the last three decades are unaffected. Add to it trans-generational epigenetic effects, in which the consequences of exposure to contaminants may actually be inherited, and you begin to realize we could be entering an era of rapid, exponential decline of IQ levels.
Gerald Crabtree adds to it the perspective of a geneticist:
"New developments in genetics, anthropology and neurobiology predict that a very large number of genes underlie our intellectual and emotional abilities, making these abilities genetically surprisingly fragile… If an average citizen from Athens of 1000 BC were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions, with a good memory, a broad range of ideas, and a clear-sighted view of important issues. Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues."
But would we even notice the difference?