IQ is an approximate measure of a person’s intelligence. Research has revealed that our potential intelligence is highly attributable to the genes that we inherit. See: What is the average percentage that genes contribute to our overall intelligence/IQ? – Intelligence and IQ However, the interaction of our genetics with the environment is a major determinant of the intelligence and the IQ that we acquire.
By the time you emerged from your mother’s womb, your brain contained about 100 billion neurons ready and waiting to connect with each other in response to the sensory experiences of your infancy. During your first two years on the planet, the neurons in your brain connected, in what are called *synapses*, at the rate of about 2 million per second, so that by age 2, your brain had about 100 trillion synapses–twice the number you have now.
Neural Pruning
Unable to sustain the biochemical reactions across all these synapses, your brain entered a stage known as *neural pruning*, removing the synapses for which there was little use. Your brain was fine-tuning itself to function effectively in the environment into which you were born. So much in this early stage of your brain development determined who you are today.
In the years following infancy, your brain continued to restructure itself in accordance with environmental stimuli. Early demands for certain types of cognitive tasks such as, learning a language or counting, played a role in determining which cognitive capacities would become most highly developed. Stanford University neurologist David Eagleman observes:
*In a sense, the process of becoming who you are is defined by carving back the possibilities that were already present. You become who you are not because of what grows in your brain, but because of what is removed.*
The Development of the Brain through Adolescence
The next dramatic phase in your brain growth occurred just before puberty when a proliferation of neurons and synapses appeared in your prefrontal lobe. This is the part of the brain associated with rational thought and executive function. A late phase in the evolution of the human brain, it provided you with a capacity for problem solving, deductive thinking, and drawing inferences–processes typically described as “higher order thinking skills.”
Another round of rapid and extensive production of neurons and synapses followed by extensive neural pruning, occurred when you entered puberty, significantly modifying and restructuring your neural network. By the end of adolescence, the pruning resulted in a decrease of between 5 and 10 percent of your brain mass, but your brain had efficiently attuned itself to the environment in which it would need to function. See contours of the prefrontal cortex at: https://www.youtube.com/watch?v=m0rHZ_RDdyQ
When we are motivated by friends, family, academic requirements or natural curiosity to engage in intellectual activity, such as learning a new language, learning to play a musical instrument or studying advanced mathematics, we are stimulating the brain and building neural connections that enhance our intellectual capabilities and therefore, our IQ. While formal education is an excellent way to achieve this intellectual growth, there are so many other ways to achieve this result such as reading, observing, exploring and interacting with others. Many highly intelligent people such as, inventor Thomas Edison, physicist Michael Faraday, and mathematician Srinivasa Ramanujan never had an extensive formal education, yet they each had a high IQ. As an old friend of mine once observed, “Education is a wonderful thing, but there is no substitute for brains.”
