The interesting question involves how a child’s environment affects not only there specific day-to-day behavior, but how it enhances their overall intelligence. Will a child that has more experiential input be smarter?

In an increasingly urbanized world, because of safety concerns, children cannot run freely outside and learn about the world through play, interaction among peers, exploring cool new places, and simply just being kids. Thus, is it possible for a child to grow, become knowledgeable, and eventually smarter if they are not allowed to be children? Well, there is an overwhelming wealth of information that supports this contention and with the findings I mentioned above - passive experiences - videos, DVDs, interactive gaming systems (video games), etc, - just don’t work!

One of the very first individuals to begin this research – “Determining how Mammals Learn” – was Santiago Ramon y Cajal, who in 1906 won a Nobel Prize in Physiology and Medicine by demonstrating that the brain was composed of individual nerve cells. It was Cajal’s “Neuron Doctrine” that laid the basic groundwork for how we have viewed the nervous system, namely as individual NEURONS (nerve cells), communicating with each other at junctions called SYNAPSES. These junctions are made between AXONS and DENDRITES. In the easiest terms, an axon carries signals AWAY from the nerve cell and the dendrites carry them TOWARD the cell body. At each synapse, nerve impulses trigger the release of chemical NEUROTRANSMITTERS (seratonin or dopamine are examples of N.T.), which act on the next adjacent neuron. The speed of the impulse along a chain of nerve cells depend upon several factors including, but not limited to, the number of Axons and Dendrites and the MYELINATION of the Neural processes. One, single nerve cell has since been shown to have thousands of these synaptic connections on its cell body as well as on the AXONS and DENDRITES. Imagine the most densely branched tree you have ever seen and that that will give you a small idea as to what ONE Nerve cell and its axons and dendrites may look like.

Now, before everyone jumps on me for all the dry, boring terminology (which I put at the end of the article) and the fact that these studies include testing done on smaller mammalian brains, (i.e., rats, pigs, dogs, etc.). Please realize when these experiments were conducted there were no CAT scans, or more importantly MRI’s, and let’s be practical, many of the conditions the researchers created cannot ethically be done to humans and I don’t think anyone would be too keen on them dissecting a child’s brain to see the results! Also, the findings are relevant because the basic anatomy of all mammalian brains, especially pigs for some reason, share an enormous amount of similarities to the human brain, especially the core structures.

In the 1960’s, researchers at the University of California Berkley began to focus on whether experience could produce observable changes in the size and number of the structures identified by Cajal. These researchers started with genetically similar rats (littermates) and divided them into 3 experiential groups. GROUP 1 was called “The Isolation Condition”, the rats were caged alone in a dark, quiet room, with plenty of food and water, but unable to touch or see any other rats. Group 2 was called “The Social Condition”. These rats lived three to a cage and were fully exposed to each other and the conversations and everyday activities of the lab technicians and they could freely view the third group. GROUP 3 was named “Environmental Complexity and Training”. Here dozens of rats lived together in a large cage and got to play with toys, run through mazes and around obstacles, the arrangement and patterns which were changed everyday (any of this sound familiar yet?) In addition, these rats were regularly handled by people daily. Within only 10 WEEKS the CEREBRAL CORTEXES of the rats in the “Environmentally Complex and Training” Group weighed an average of 5% more than those of the other two groups, even the “Social Condition” group that “watched” the other rats everyday! In further testing the “Complex” group routinely outperformed the other two groups in negotiating complex, problem-solving mazes.

An interesting side note to this was, the average body weight of the “Complex” group was also 7% less than those of their “Isolated” and “Social” cousins because of their daily activity and exercise. ‘This phenomenon – a higher brain-to-body-weight ratio – is also found in wolves that live in physically demanding, experience rich environments. Pound-for-pound, wolves have about a 20 PERCENT bigger brain than do Fluffy and Fido, your domestic dogs at home!’ (Kerasote, 2007)

In the 1970’s, William T. Greenough, a psychologist at the University of Illinois continued this line of investigation and demonstrated that it wasn’t brain size alone that proved intelligence. The rats he reared in the “Complex” Environment had more Dendrites, Synaptic Junctions, and Axon collateralizations per neuron than their “Isolated” counterparts. And not just “more”, but hundreds of thousands more connections! Greenough concluded that the increased branching creates a greater capacity for processing information - INTELLIGENCE.

The same phenomenon is seen again in the real world of canids. ’Wolves are vastly superior to domestic dogs at solving complex problems like opening doors or escaping from pens, and they can easily plan and execute coordinated attacks on much larger prey, which pack dogs are unable to do. In short, the wolves that live in more challenging environments are able to exhibit much more complicated and intelligent behaviors.’ (Kerasote, 2007)

In the 1990’s Greenough began working with James Black in a series of attempts to outline the attributes of “Stimulating Environments” that produced these impressive results. In an experiment that ALL of us can relate to, they again compared “Isolated, Sedentary” rats with rats that were exercised on a treadmill everyday. These two groups were, in turn, compared to “Acrobatic Rats”, who were again put in challenging mazes that winded around, through, and over challenging, elevated and varied obstacle courses (Again, sounds really familiar, doesn’t it?). The findings, that would have saved the most recent “Baby-Einstein” researchers countless man-hours and several hundred-thousands of dollars, showed that there was absolutely NO DIFFERENCE between the brains of the couch-potato rats and the treadmill rats! Their brains weighed and appeared exactly same! But, the cerebral cortexes of the “Acrobatic Rats” were SIGNIFICANLY heavier and neurally dense! Greenough and Black concluded that learning must encompass engaging and active tasks rather than passive participation! Wow, what a shocker!

Berkley researchers also found the same results when they tried to identify which stimuli had the most powerful effect on brain development. They too, found that it wasn’t just exercise, “passive” participation, or visual stimulation that improved intelligence. Handling, petting, and love didn’t produce larger brains either. Neither did sitting around singing songs, watching interesting T.V, or looking out the window.

The ONLY THING that consistently and repeatedly improved the neural development in the cerebral cortex of the rats was the freedom and experience to roam large, interesting, challenging, object filled spaces! (Again, does any of this sound familiar?) They also found that not only did the “complex” rats vastly increase the number of axon branches, dendrites, and synaptic junctions, they showed increased “Myelination” along the lengths of the axons and dendrites, thus leading to even faster and more efficient neural messaging among the already significantly increased number of neural connections.

These findings may give insight as to why animals who live in zoos become depressed and oftentimes have shorter life expectancies than their wildlife counterparts, even when they have advanced medical care, balanced diets, active sex lives, and authenticated, (although miniaturized) habitats. Compared to the real thing, the “natural” experiences of life, captivity is BORING!

Think of all the neurotic dogs in the world: the biters, the barkers, the chewers, the diggers, and those who soil their own spaces when left alone or run along a fence for hours upon hours. Author Jon Katz states in his book, “The New Work of Dogs” states, “Dogs are rarely permitted to solve problems.” They are not even given the “chance to figure out what to do. They just look to their humans, sic(parents), for that direction. And we humans, sic(parents), are all too willing to ALWAYS give them that direction!” WOW, doesn’t that sound eerily similar to how we treat small children??

So what then might be said when applying the numerous findings concerning mammalian brain development and the correlation to intelligence in children?

Simply this: Given the right stimuli and experiences, children’s brains are highly adaptable and these experiences may lead to increased intelligence!

The neurologist Antonio Damasio touches upon this issue in his book “Descartes’ Error”, where he describes how some of our genes CANNOT unfold to their full potential until they have been modified by EXPERIENCE. As he says, “What happens among cells, as development unfolds, (experiences) actually control the expression of the genes that regulate development in the first place. As far as one can tell, then, many structural specifics are determined by genes, but another MUCH LARGER NUMBER of structural specifics can only be determined by the activity of the living organism itself, as it develops and faces NEW EXPERIENCES throughout its life.”

More simply stated every child MUST experience new things on their own if their full developmental potential is going to be met. They must fall down and get back up. They must take that first terrifying step on the balance beam by themselves. They must be allowed to succeed and fail on their own. They must learn how to count before they can learn algebra. They cannot learn to read by being read to. And they cannot become smarter by watching educational videos and playing video games, they have to get out of their mom’s arms and interact with other children, they have to play, they must sing, they need to dance, they have to laugh, they have to be children, and as often as possible:They MUST MOVE THEIR BRAINS!

Neuron – A nerve cell, the structural and functional unit of the nervous system. Neurons consist of a cell body, and its processes, an axon, and one or more dendrites. Neurons function in the initiation and conduction of impulses. Impulses are transmitted to other neurons or cells by releasing neurotransmitters at synapses.

Axon – A process of a neuron that carries impulses away from the cell body. Axons may or may not possess Myelin sheaths or neurilemma. Axons are generally straight, and most end in synapses in the central nervous system, ganglia, or in effector organs (e.g. motor neurons). They may give off side branches or collaterals. An axon and its sheath constitutes what we call a nerve fiber.

Dendrite – A branched cytoplasmic process of a neuron that conducts impulses to the cell body. There are usually several dendrites to each neuron. They form synaptic connections with other neurons.

Synapse – The space between the junction of two neurons in a neural pathway, where the termination of the axon of one neuron comes in close proximity with the dendrites of another. The impulse traveling along the pre-synaptic neuron to the end of its axon releases chemical neurotransmitters that either stimulate or inhibit the post-synaptic neuron. Synaptic transmission is always in one direction only.

Neurotransmitter – A substance that is released when the axon terminal of a neuron is excited and acts by inhibiting or exciting a target cell. N.T. disorders have been implicated in the pathogenesis of a variety of neurological and psychiatric illnesses.

Myelin – The phospholipid-protein that forms the sheath around neural fibers. It acts as an electrical insulator and increases the velocity of impulse transmission along a nerve fiber.

Myelination – Process of the growth of Myelin sheath around nerve fibers.

Cerebrum and Cerebral Cortex – The largest part of the brain, consisting of two hemispheres separated by a deep longitudinal fissure. The Cerebrum is concerned with sensations (the interpretation of sensory impulses) and ALL voluntary muscle activities. The Cerebral Cortex is the seat of consciousness and the center of the higher mental faculties such as MEMORY, LEARNING, REASONING, JUDGEMENT, INTELLIGENCE, and EMOTIONS.

Notes:

Santiago Ramon y Cajal, “Recollections of My Life”, vol. 8, part 2 (Philadelphia: American Philosophical Society, 1937), 373.

Edward L. Bennett et al., “Chemical and Anatomical Plasticity of the Brain”,: Science 30, vol. 146 (October 1964): 610-619.

Raymond Coppinger and Richard Schneider, “ Evolution of Working Dogs”, in “The Domestic Dog”, ed. James Serpell (Cambridge, England: Cambridge University Press, 1995), 33.

“Weightlifting for the Mind: Enriched Environments and Cortical Plasticity”,: http//www.brainconnection.com/topics/printindex.php3?main=fa/cortical-plasticity.

Fred R. Volkmar and William T. Greenough, “Rearing Complexity Affects Branching Dendrites in the Visual Cortex of the Rat”, Science30, vol.176 (June 1972): 1447.

William T. Greenough, James E. Black, and Christopher S. Wallace, “Experience and Brain Development”, Child Development 58 (1987): 539-559.

Jon Katz, “The New Work of Dogs”, (New York: Random House, 2004), 18.

Antonio Damasio, “Descartes’ Error: Emotion, Reason, and the Human Brain”, (New York: Penguin Books, 2005), 109.

Jeffrey Moussaieff Masson, “Dog’s Never Lie About Love”, (New York: Crown Publishers, 1997), 36-37.

Ted Kerasote, “Merle’s Door: Lesson’s from a Freethinking Dog”, (New York: Harcourt, Inc., 2007), 60-63, 301.