Are Humans Becoming Less Intelligent?



Well, one thing’s for sure. Our brains are getting smaller. That’s right, that’s what scientists now claim. The consensus among those with enough intelligence left to care and do the research, is that our brains are much smaller than the brains of our ancestors some 20,000 years ago … and what’s more, this loss of brain mass is actually related to the introduction and widespread influence of agriculture.

Keep that in mind the next time you chomp down a sandwich or a plate of pasta.

Over the past 20,000 years, the average volume of the human male brain has decreased by a whopping 10%, from 1,500 cubic centimetres to 1,350 cubic centimeters. That’s a chunk of grey matter about the size of a large meatball. And guess what girls? Your brains have shrunk by the same proportion.

If IQ as it’s determined today is a true measure of human intelligence, then we are definitely heading in the wrong direction. Never mind the dumbing down of America, we’re talking whole world stuff here, meaning everyone everywhere.

Research and clinical testing of our species suggest human intelligence is on the decline. The data indicates that Westerners have lost 14 I.Q. points on average since the Victorian Era.

The Victorian Era by the way, is a period of British history that lasted 64 years. It’s defined by Queen Victoria's reign from 1837 until her death in 1901.

IQ is an acronym for “Intelligence Quotient”. IQ is a score derived from one of several standardized tests designed to assess human intelligence. The most commonly used individual IQ test series is the Wechsler Adult Intelligence Scale for adults and children. Testing includes subindexes of verbal comprehension, working memory, perceptual organization and processing speed.

Dr. te Nijenhuis and colleagues analyzed the results of 14 intelligence studies conducted between 1884 to 2004, including one by Sir Francis Galton, an English anthropologist and a cousin of Charles Darwin.

Each study gauged participants visual reaction times, determined by how long it took them to press a button in response to seeing a stimulus. Reaction time reflects a person’s mental processing speed, and is considered an indication of general intelligence.

In the late 19th Century, visual reaction times averaged around 194 milliseconds. In 2004 that time had grown to 275 milliseconds. Reaction time has increased. Research that corroborates an apparent rise in intelligence suggests a rise in I.Q. scores since the 1940s, a phenomenon known as the Flynn Effect.


The Flynn effect is named for James R. Flynn, who did much to document it and promote awareness of its implications. Flynn is a professor of political studies at the University of Otago in New Zealand.

But Dr. te Nijenhuis suggests the Flynn Effect reflects the influence of environmental factors such as better education, hygiene and nutrition, and that these factors actually mask the true decline in genetically inherited intelligence in the Western world.

Another prominent researcher, Dr. Richard Lynn, a psychologist at the University of Ulster, has calculated the recent decline in human genetic potential. He thinks we are definitely getting dumber.

Dr. Lynn used data on average IQs from around the world in 1950 and 2000. He discovered that our collective intelligence has dropped by one IQ point. Dr Lynn predicts that if this trend continues, we could lose another 1.3 IQ points by 2050.

Several theories have been proposed to explain why we’re losing intelligence as a human collective, and guess what? They’re all related to fitness, nutrition, health and wellness, which is why we need to pay attention.

Here are seven variables to consider.

No. 1 - Toxic chemicals in the environment can reduce intelligence. Examples include flame retardant, lead found in children toys and many lipsticks, certain pesticides, fluoride and radiation.

Radiation can reduce brain size and many epidemiologic studies show that extremely low doses of radiation increase the incidence and risks of diminished intelligence. Common sources include atmospheric residue from past nuclear bomb testing, excessive sunlight, TV, cell phones, microwaves and cigarettes.

No. 2 - According to the theory of evolution, humans evolved from a superfamily of apes called hominoidea roughly 28 million years ago, which evolved into the Great Apes some 15 million years ago. The Great Apes include humans, chimpanzees, bonobos, gorillas and orangutans.

The main point here is that we evolved from and became genetically dependent on a diet rich in long-chain omega-3 fatty acids, especially EPA and DHA, found principally in seafood and wild game, not plants.

In biology humans are classified as omnivores, not carnivores or herbivores. This status gave us, and still does, an enormous advantage of being able to eat and digest a great variety of foods from nature. Unfortunately this also furnishes us with the ability to eat and digest the worst food in the world, namely, the SAD or Standard American Diet.

Originally, we consumed a balanced nutrition ratio of one omega-6 fatty acid to one omega-3 fatty acid. In some ancient cultures renowned for good health and longevity, and in many fishing cultures still today, the ratio remains in favor of omega-3.

Unfortunately, this ratio has been twisted to our current pro-inflammatory ratio. Our intake of fatty acids today is completed dominated by omega-6 fatty acids, including cis-linoleic acid and arachidonic acid. Most of these fats are damaged, rancid and mutated by heat, light and oxygen. This ratio is definitely harmful to our species. Intake in average adults and children in North America is as high as 10 or 20 parts omega-6 to one part omega-3.

Wild game animals like antelope, bison and caribou have much higher levels of essential Omega 3 fatty acids than their artificial domesticated counterparts, because wild animals eat green grass as a staple.

But like our front lawns, trees and flowers, almost of all our food animals have been modified genetically directly, or by decades of cross-breeding and hybridization. The end result is more profit for some but less health for the majority. In our society what looks good is often hollow, weak or incomplete.

To create a diet rich in naturally occurring Omega-3s, you have to eat sardines, shellfish, wild salmon, pasture-raised grass-fed animal products, walnuts, flax and chia seeds ON A REGULAR BASIS. Why? Because omega-3 fats are known to boost intelligence and help prevent cognitive decline.

No. 3 - Here’s a reason you might not think of. According to research presented at the 110th General Meeting of the American Society for Microbiology in San Diego, exposure to specific bacteria in the environment, already believed to have antidepressant qualities, can positively affect learning behavior.

Mycobacterium vaccae (va-kee) is a natural soil bacterium which people normally ingest or breathe in when they spend time in nature.

Dorothy Matthews of The Sage Colleges in Troy, New York, conducted research with her colleague Susan Jenks. They found that mice fed live Mycobacterium va-kee navigated through mazes twice as fast compared to control mice. The mice on the bacteria also demonstrated less anxiety.

In a second experiment the bacteria were removed from the diet of the experimental mice and they were retested. While the mice ran the maze slower than they did when they were ingesting the bacteria, on average they were still faster than the controls.

Today we’re obviously not getting as much direct exposure to soil as our ancestors did. How much time do we spend in the backyard gardening, on farms tilling soil, herding sheep in the mountains or hunting and gathering? When’s the last time you picked up a handful of live soil and let it run through your fingers? Of course another way to raise your healthy bacteria count as our grandparents and ancestors did, is to eat more fermented foods that contain healthy bacteria.

No. 4 - Exercise boosts intelligence. Our ancestors physically moved a hell of a lot more than we do today! Even our most highly trained athletes pale in comparison to the work load of ancient man. Today even walking has been eradicated from our daily duty.

But if form follows function, which it does in science, engineering and architecture, and we certainly have legs designed for walking and running, it makes sense that not using our limbs will hasten body decay throughout the entire body, often seen in inactive people long before their time.

We know that children with learning difficulties have improved attention task capacity when exercised, and seniors who learn new dance steps benefit from the stimulation of grey cells in the brain. Exercise oxygenates the brain, stimulates better circulation and literally uses the form Nature designed us to use. Use it or lose it still applies. Perhaps it always will.

No. 5 - High levels of cortisol released when one is under continuous, unrelenting stress and poverty can physically impair the brain and our ability to learn. Our hunting-gathering progenitors had more leisure time and a more playful attitude than we do today. Certainly, excess uncontrolled stress is a killer and ruins the quality of our life. Exercise and good nutrition comes to mind here.

No. 6 - Dr. te Nijenhuis makes this observation of the facts. Women of high intelligence tend to have fewer children than do women of lower intelligence. This negative association between I.Q. and fertility has been demonstrated time and again in research over the last century. In other words, excessive baby making seems to deplete both the mind and body, and this has a negative effect on the intelligence of the offspring.

No. 7 - Dr. Gerald Crabtree, professor of pathology and developmental biology at Stanford University, says that the reduction in human intelligence began around the same time that genetic selection became more relaxed.

According to selection theory, individuals with advantages or "adaptive" traits tend to be more successful than their peers reproductively, meaning they contribute more offspring to the succeeding generation than others do.

When these traits have a genetic basis, selection can increase the prevalence of those traits, because offspring will inherit those traits from their parents. When selection is intense and persistent, adaptive traits become universal to the population.

Crabtree says this reduction in genetic selection occurred as our ancestors began to live in more supportive high density societies, namely large cities with access to a steady supply of food. But easier access also means less labor and less physical activity and unfortunately today, this also includes ample access to huge varieties of toxic refined factory food. So do you think we’re losing our intelligence marbles? Are we getting less or more capable of self-regulating our health? Are people as a general rule doing what is necessary to sustain their own form, health and wellness?

You decide, but before you do, take a good look around you. Watch what people do, but also take note of what they don’t do. You’ll be amazed by what you see and don’t see.

As always...Stay well and Live Free

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