In the same way that we can breed physical and personality traits into dogs over only a few generations, the intelligence of the human race could (likely) be progressively enhanced via artificial selection, genetic engineering, iterated embryo selection, or cloning. However, all of these are ethically off-limits. Therefore, I will limit my discussion to the individual level.
On an individual level, the largest determinant of intelligence is genetics coupled with the first ten or so years of life (i.e., the interaction between genes and environment). During this time, the brain adapts to environmental demands. Used synapses are kept and expanded, while unused synapses are pruned (“Use it or lose it.”).
By the age of 10, the primary wiring of the human brain is established. However, for the next decade or so, the brain remains quite plastic, and significant changes in the brain’s blueprint, including small gains in fluid intelligence, are still possible. Thereafter, from a “hardware level” perspective, “raw” intelligence (g-factor) is mostly set by late adolescence and can only be improved to a minuscule extent (if at all).
However, gains in “practical” intelligence, which is essentially about reaching and sustaining peak performance, are still possible. Obviously, practical intelligence is partly based on brain function, which can be modulated in many ways. Some of these ways are the subject of the following article.
The above is only a fraction of the article. This article is currently undergoing final revisions and is expected to be published within the next few weeks to months. To receive a notification upon its release, sign up for my newsletter.
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